The Sea to Summit Ultra-Sil Shopping Bag is a tiny reusable shopping bag that is made of the same high tear strength fabric we make our pack covers, compression sacks and stuff sacks of, so theyre amazingly strong and durable. All of the stress points have bar-tacked reinforced stitching. You can fill these shopping bags to capacity week in, week out and they will keep performing like new. And because this reusable Ultra-Sil Shopping Bag is so compact and lightweight you can stash it anywhere - the tiny packed size clips easily onto a key ring with the attached carabiner or tucks in a purse or in a jacket pocket, so you never have it out of reach.