Jay wearing the Moonstone Cirrus Ultralight Jacket on the Continental Divide Trail in the Southern San Juan Wilderness, Colorado.
The 12.7-ounce (360 gram) Moonstone Cirrus jacket uses a 15 denier high-tenacity ripstop fabric for the shell and lining, along with Dupont Thermolite Micro insulation. The Cirrus has a light shell and a higher lofting 2.4 oz/yd2 insulation, versus the 1.8 oz/yd2 insulation used in many other ultralight jackets. As such, it maintains a loft/weight performance similar to minimalist jackets while retaining features like pockets and a full zipper. With a good DWR and thick insulation, the Cirrus Ultralight performs well under the worst climatic conditions. Its fit allows minor gymnastics without exposing body parts to the elements. Although the hand warmer pockets are fine around camp or town, they are too low and are covered by a pack’s hip belt when backpacking.
- Maintains good loft/weight performance while retaining features like pockets and a full zipper
- The 15 denier x 40 denier high-tenacity ripstop is only 1.1 oz/yd2
- Shell looks great, and held up to hard use
- Great fit with underarm gussets for good freedom of movement
- Dupont Thermolite Micro insulation (2.4 oz/yd2)
- Comfortable pockets, although they are too low for use with a hip belt
- Heavier than some minimalist jackets with similar warmth
• Garment Style
|Full zip jacket|
• Fabric Description
|1.1 oz/yd2 (38 g/m2) 15d high-tenacity nylon ripstop with Super DWR|
• Insulation Description
|2.4 oz/yd2 (80 g/m2) Dupont Thermolite Micro|
• Other Features
|Two zippered hand warmer pockets with FieldSensor brushed tricot lining. One zippered inside napoleon pocket. Separate stuff sack included.|
|12.7 oz (360 g) as measured, size M (Manufacturer’s specifications: 13 oz). Stuff sack adds 0.5 oz (14 g).|
|0.4 in (1.0 cm)|
• Model Year
|Fall 2004 (preproduction sample tested)|
The Cirrus Ultralight has 2.4 oz/yd2 Dupont Thermolite Micro insulation in both the body and sleeves. The Thermolite insulation provides about 0.4 inches of single layer loft. For comparison, the weight and volume of Thermolite Micro is comparable to 216-fill power down (216 in3/oz). The insulation is quilted to the outer shell fabric of the Cirrus Ultralight, but not to the inner lining. This insulation is highly compactable, drapes well, and holds up to hard use and washing.
I tested the jacket in temperatures down to 25°F in both high winds and wet conditions, with the jacket fully zipped and hem draw cord cinched, while wearing a light base layer. I was warm in the jacket at temperatures above freezing when resting, and comfortable to the upper-20s in the Cirrus when active. Heat retention is very good throughout the jacket. Moreover, the superb fit and resulting freedom of movement reduced the amount of cold air entering the jacket as I moved.
I tested the breathability of the jacket under the same conditions. It performs well while at rest and wearing dry clothing. The breathability becomes a bit hampered when active, particularly when base layers are damp. The tightly woven fabric does not breathe as well as Pertex Quantum.
Moonstone uses a 1.1 oz/yd2 high-tenacity nylon ripstop fabric for both the shell and liner of the Cirrus. This fabric has a 15 denier fiber in one direction woven to a “super full dull” 40 denier fiber in the other for strength and reduced shininess. The final product held up well and has an attractively dull finish.
Moonstone treated the fabric with a Super DWR coating that does an excellent job of shedding light rain. Heavier rains soak through with time. However, the synthetic microfiber insulation does retain most of its loft when wet. Drying time is a bit slower than I would have liked – probably hampered by the lower breathability of the shell fabric.
The Cirrus Ultralight provides plenty of arm mobility without exposing the wrist or lower torso. Illustrated here by Jay’s full arm extension ( 31.5 inch sleeve length), the sleeve still shows wrinkles with the wrist fully covered.
The Cirrus Ultralight is sized to fit over a base layer and underneath a shell. The sleeves are long enough to completely cover my hands if they are balled into fists, and remain at the wrist with my fairly long arms extended or raised (see photo). Torso articulation is also very good. When I hold my arms straight out the hem does not rise. The hem rises only about 2 inches when I raise my arms above my head. Hats off to underarm gussets!There is sufficient length in the jacket to permit the 2-inch rise without exposing the pant’s waistline. The collar on our prototype sample seems slightly big when wearing the Cirrus Ultralight with a collarless base layer. However, I found the fit works well with a collared base layer or balaclava. In addition, Moonstone has made some changes to the production Cirrus Ultralight to improve the collar’s shape.
The FieldSensor brushed tricot lining in the two zippered pockets of the Cirrus Ultralight provides instant warmth to numb digits. The pockets are located low on the sides of the jacket and unfortunately are inaccessible while wearing a pack hipbelt. A third zippered pocket is located Napoleon style on the inside left chest.
Opening the full-length front zipper is the best means for regulating temperature. The Cirrus Ultralight uses a lightweight, but durable, #5 single slider, one-way separating YKK coil zipper. The use of a one-way zipper eliminates venting by unzipping the jacket from the bottom. However, a light shock cord at the hem allows some adjustment to the hem opening thus permitting some lower torso ventilation. The jacket has non-adjustable sleeve cuffs formed of elastic sewn into the shell fabric.
After enduring 76 miles on the Continental Divide Trail in Southern Colorado, numerous other hikes, mountain bike rides, and several washings, the Cirrus is in good shape. Even light encounters with brush are not much of a problem as I discovered while hanging bear bags in the thick pines of southern Colorado. When worn without a shell, the material is not suited to more serious bushwhacking or alpinism. Minimum weight was a primary design objective for this garment; durability was secondary. Nevertheless, stitching is top notch. Moonstone did not miss an opportunity to reinforce with bar tacks or double stitching in critical areas.
Shell fabric that is relatively durable for its weight, exceptional freedom of movement, and the minimal weight of the Moonstone Cirrus Ultralight combine to create a nice overall package at a reasonable price of $140.00.
Recommendations for Improvement
Very little needs improvement. Our only recommendation is to raise the hand warmer pockets so they can be accessed while wearing a pack with a hipbelt.
Don did you want this to be bulleted. It’s not in the reviewer guidelines you sent me.