The Ultra-Sil Nano Shopping Bag is constructed using lightweight 15 denier siliconized nylon. Its generous 25L capacity is reinforced by bar-tacks so it easily supports loads in excess of 45 lbs / 20kg-a lot more than you'll comfortably carry over your shoulder! This tiny reusable shopping bag is amazingly strong and durable. We've also made sure that 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. Because the Ultra-Sil Nano Shopping Bag is so compact and lightweight you can stash it anywhere - the tiny packed size clips easily onto a key ring, a carabiner, or tucks in a purse or in a jacket pocket, so you never have it out of reach.