I got one of these and it's great for the money. 18oz on my scale. I got it to strap on top of my rear rack for bike packing, wanting a tougher fabric than I would normally seek for hiking. The straps are nothing to rave about, but they are padded and would fine for UL day hikes when doing bike/hike hybrid trips, rafting, etc
http://www.sierratradingpost.com/seattle-sports-h2o-gear-waterproof-pack-small~p~2579x/
Specs:
Backpack straps and durable haul handle
Welded dry-bag construction
Dimensions (HxWxD): 24x13x7"
Capacity: 2184 cu.in.
Weight: 1 lb. 5 oz.
Material: Vinyl-coated polyester with nylon webbing and foam-padded shoulder straps
Made in USA.
