This gear review will cover two foot-insulation options from Rab; the Rab Expedition Slipper ($175, 6 oz / 170 g per pair) and the Rab Hot Socks ($65, 5 oz / 135 g per pair). Both pieces of gear are lightweight options to add warmth to camp insulation, though they differ in terms of insulation level and type, materials, and intended use.

A Rab Hot Sock and Rab Expedition Slippers on a white background.
Rab Hot Socks (left) and Rab Expedition Slipper (right). Photo: Rab

The Rab Expedition Slipper is 800 FP down and intended for use inside the sleep system. The Rab Hot Socks are synthetic insulation and sport an abrasion-resistant footpad to allow for use as a camp shoe if desired.

About This Review

The Rab Expedition Slipper and Rab Hot Socks were my 2020 sleep system companions through high alpine routes, shoulder-season treks, and winter treks alike in the Canadian Rockies.

Both products in stuff sacks next to a water bottle for comparison
Rab Hot Socks, Rab Expedition Slipper, and Nalgene packed size comparison

Features and Specifications

Rab Expedition Slipper

  • 800 FP hydrophobic goose down
  • one-handed drawstring closure
  • elastic ankle-shaper
  • elastic arch-shaper
  • Pertex Quantum inner and outer
  • included stuff sack
  • hang loops
  • one-handed shock cord closure
  • claimed weight: 6 oz (170 g) per pair
  • measured weight: 5.2 oz (149 g) per pair / size: large
The Rab Expedition Slippers unpacked and next to a standard Nalgene bottle for size comparison
Rab Expedition Slipper size comparison.

Rab Hot Socks 2.0

  • Primaloft synthetic insulation
  • 500D Cordura sole
  • Pertex Quantum outer
  • stretch fleece ankle
  • fleece and Pertex Quantum inner
  • included stuff sack
  • claimed weight: 5 oz (135 g)
  • measured weight 5.4 oz (154 g) / size: extra large
The Rab Hot Socks unpacked and next to a standard Nalgene water bottle
Rab Hot Socks size comparison

Performance Analysis

Since this is a Limited Review, a detailed performance analysis based on long-term use will not be presented. Instead, performance observations and issues are noted below.

Rab Expedition Slipper


The instant I slipped the Rab Expedition Slipper on, my feet instantly felt warmer. The 800 FP down is lofty, and the drawstring closure around the ankle ensures heat retention. This is the first slipper I’ve had that provides real four-season comfort.


Compared to packing a warmer quilt or a pair of heavy wool socks, the Rab Expedition Slipper has a small weight penalty, especially considering its warmth value. The manufacturer estimate of how much the Rab Expedition Slipper weighed was generously over the measured weight.


The Rab Expedition Slipper has a soft Pertex Quantum inner and outer, which feels like silk on the skin and glides nicely inside a quilt or sleeping bag. The Expedition Slipper also features a loose elastic tensioner in the insole and at the ankle, making the slipper fit well around the foot.


The Rab Expedition Slipper is a slipper, not a hut bootie, and is not designed for wear outside of the quilt or for walking around.


The Rab Expedition Slipper has no traction as it is not designed for weight-bearing walks.


At about the size of a Nalgene once packed down, the Rab Expedition Slipper is a pretty tiny addition to a sleep system, though there are more packable options (like products from Goosefeet Gear).

A woman crosses a snowy creek with a mountain in the background.
Sunset Pass temps dropped -2 F (-19C). It was my inspiration for more insulation for my feet on winter trips.

Rab Hot Socks


Rab Hot Socks are moderately warm socks for wearing inside the tent. They provide additional warmth in moderate shoulder-season conditions but do not offer four-season warmth.


Rab Hot Socks are of moderate weight but do not pack the insulation punch of the Rab Expedition Slipper for slightly less weight.


With no drawstring or elastic fittings at the ankle or insole, Rab Hot Socks feel a bit like a sloppy reading sock. They are soft on the inside but do not have the same cloud-like feeling as the Rab Expedition Slipper.


To their credit (and weight-saving detriment), Rab Hot Socks are a durable product. Their Cordura sole means if you happen to take a cautious tread, you are less likely to rip the fabric. However, walking outside your tent in any sock is an at-your-own-risk activity. I like my gear and my feet, so I wouldn’t.


Rab Hot Socks are socks. They do have Cordura soles, but I would not say that counts as traction.


Stuffing Rab Hot Socks is a bit of a chore, especially compared to their down-filled cousin, the Rab Expedition Slipper.

A misty mountain ridgeline with green vegetation in the foreground.
High humidity days and freezing nights on Corona Creek encouraged me to purchase the Rab Hot Socks for high alpine summer trips when the extreme insulation of down was not required.

What Makes the Rab Expedition Slipper Unique?

The Rab Expedition Slipper is one of the only widely-available (non-cottage industry) down slippers out there. Unlike most insulated slippers available from major retailers, it has soft soles that don’t interfere with using it as a sleeping sock. It also boasts one of the best anatomical designs I’ve seen for insulated sleep slippers.

  • down fill, wide availability
  • soft sole for sleeping
  • sophisticated, ergonomic design

Down Fill, Local Availability

After a few miserable winter nights where I was alternating wrapping my down puffy around my feet and my torso, I decided I needed a better system. Thick wool socks just weren’t enough. After searching several different manufacturers, I found many insulated booties were synthetic, not down, and I am partial to down. Though there is a slightly better warm-when-damp ratio for synthetic, it’s not as warm, packable, sustainable, durable, or lightweight as down. In dry winter conditions, I’d rather have the pros of down than the insurance of synthetic.

When it came to ordering a down slipper, Rab offered the most selection at local retailers. Though they were a special order, they arrived in less than a week. If I had ordered from a cottage gear company, I could have waited months for a custom product to arrive in the remote area where I live.

Soft Sole for Sleeping

Many down booties and slippers I looked at weren’t actual sleeping items; they were designed to sit and walk around in a hut or ski chalet. I needed a true down sock that was comfortable and packable. The Rab Expedition Slipper fit the bill perfectly. The soft silky fabric used in the Rab Expedition Slipper made these extremely comfortable to sleep in.

Blue down slippers against a grey background.
Rab Expedition Slippers have a soft sole, made for sleeping, not walking around in camp.

Elastic Foot Shaping

The Rab Expedition Slipper uses small pieces of elastic to create a more anatomical foot shape. The toe of the Rab Expedition Slipper provides plenty of room for a warm layer of down and air to form around the foot. Unlike other down socks and slippers (which can have a sloppy fit), I found the ergonomic design of the Rab Expedition Slipper comfortable and natural to wear.

A shot of the Rab Expedition Slippers that allow you to see the elastic panels and well-tailored fit.
The ergonomic design of the Rab Expedition Slippers makes them very comfortable, more so than other down slippers or booties I’ve used.

What Makes Rab Hot Socks Unique?

Rab Hot Socks are not as warm as a down bootie but boast the reliability of synthetic and fleece for lower-stake shoulder season or summer warmth in alpine conditions.

  • fleece synthetic insulation
  • tough sole fabric
  • excellent product availability

Fleece/Synthetic Construction

Rab Hot Socks have a synthetic fleece construction which allows them to be useful on long-term treks with high humidity where a bit of extra insulation while sleeping is required. They are comfortable and a compromise when you can’t have (or don’t need) down but still need a bit more insulation than a basic wool sock.

a close up of the Rab Hot Socks to illustrate the insulation and tough soles
The synthetic fleece insulation and Cordura soles on the Rab Hot Socks

Tough Sole Fabric

Rab Hot Socks’ soles are lightweight 500D Cordura; unlike some hut booties, they do not have a firm foam sole, which saves weight and makes them more packable than a hut bootie.

a close up of the tough Cordua soles, you can see their texture is different than the rest of the product.
500D Cordura Soles on the Rab Hot Socks

Product Availability

The best part about ordering gear from a big retailer is the ease of product accessibility. After my feet being cold on a trek, I decided I needed better insulation for my next trek (about a week later). I ordered Rab Hot Socks and they arrived in time for my next trip.

Rab Expedition Slipper Compared To…

Rab Expedition Slipper vs. GooseFeet Gear Down Socks

The most comparable item I found to the Rab Expedition Slipper was the GooseFeet Gear Down Socks. In my opinion, the Rab Expedition Slipper edged out GooseFeet Gear Down Socks because they had a better fit because of the instep and ankle’s elastic anatomical shaping. The Rab Expedition Slipper is also available from retail outlets and is easier to order in remote areas. However, if you have time and want a custom-made slipper, the Goosefeet Gear Down Socks are a great option.


These two products are entirely comparable for warmth in the same category of insulation. You can, however, order a variety of insulation and fabric options from GooseFeet Gear. Goosefeet Gear offers 850 FP down, Rab offers 800 FP down. Because higher FP down offers similar warmth at a lower weight, we’ll give the edge to GooseFeet.

Edge: GooseFeet Gear Down Socks

Product Access

As with many cottage companies, I have difficulty ordering items into my remote area. If forced to choose, I almost always select a comparable product I can get at the local outdoor outfitter. Rab offers product availability from multiple retailers across North America and the world. On the other hand, this product is currently discontinued and only available at third-party retailers. So we’ll call this one a tie.

Edge: Tie


The Rab Expedition Slipper is not a customizable product; it comes in one color, one down fill level, and four sizes. GooseFeet, however, offers a rainbow of color, fabric types, and fill levels.

Edge: GooseFeet Gear Down Socks


The Rab Expedition Slipper edged out all competition when it came to fit. Its design is more complex and sewn in several pieces with elastic to ensure perfect foot fit at the ankles and instep and includes an adjustable drawstring. Though Goosefeet Gear offers the drawstring, like the Rab Hot Socks, the overall fit is sloppy compared to the anatomical fit of the Rab Expedition Slipper.

Edge: Rab Expedition Slipper

Rab Hot Socks Compared To…

Rab Hot Socks vs. Montane Prism Bootie

Rab Hot Socks are best compared to the Montane Prism Bootie. With similar synthetic insulation and harder-wearing sole, these have the option of being a hut bootie/sleep sock cross-over if you so choose. Personally, I’d rather not use anything I sleep in for any kind of walking around, but it’s a good option for anyone inclined towards a multipurpose minimalist camp shoe.


I would say the drawstring closure and foot shape of the Montane Prism Booties make them a better foot fit but the firm sole makes them less useful for sleeping in. So it is a toss-up between the two. But I would give the edge to the Montane Prism.

Edge: Montane Prism Bootie


The Montane Prism Bootie is marginally heavier ( 6 oz / 16 6g) than the Rab Hot Socks ( 5 oz / 154g).

Edge: Rab Hot Socks


Rab Hot Socks pack down smaller than the Montane Prism Bootie.

Edge: Rab Hot Socks


Rab Hot Socks ($70) are a more expensive product than the Montane Prism Bootie ($55)

Edge: Montane Prism Bootie

Rab Expedition Slippers Strengths and Limitations


  • soft, comfortable fabric and down fill
  • drawstring closure
  • elastic foot shaping


  • a bit bulky when unstuffed
  • no slipper cup
  • no hard-wearing sole

Rab Hot Socks Strengths and Limitations


  • harder wearing fabric
  • synthetic/down combination retains some warmth when wet
  • good insulation level for warm sleepers


  • bulky
  • hard to stuff
  • heavier than down, less insulation
  • sloppy fit

Where to Buy

  • Buy the Rab Expedition Slippers here. Sadly the Rab Expedition Slippers are discontinued, but they are still available in a few places (I ordered a second pair in December 2020 without issue). A second choice item (which I don’t like as much) is the Rab Down Slipper. I am hoping Rab brings the Expedition Slipper back soon; I want a backup pair.
  • Buy Rab Hot Socks here.

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