Review on Sea to Summit Lightweight Dry Sack: Versatile & Waterproof All-Purpose Dry Bag by Juan Wilson

I ordered the small thinking it would fit in the listing: Small (4 litres), 9" flat x 15" - is it not. I believe it was about 6 x 13 inches. Here are the actual dimensions: 1 liter: 4.3 x 9.4 inches, 2 liters: 5.1 x 11.4 inches, 4 liters: 5.9 x 13 inches, 8 liters: 6.7 x 18 inches, 13 liters: 8.6 x 21 inches. 20 liters: 10 x 24 inches 35 liters: 12 x 27 inches. I ended up returning the small size and bought x-large. Most people use them for sport - I use them to carry my lunch in my backpack. I bike to work and lost three backpacks to spilled lunches (bag one: spaghetti sauce got stuck in the mesh tail that won't wash out; backpack 2: a night glass of oat jar, leaving tiny broken glass everywhere; backpack 3 (leather with cotton lining): olive oil salad dressing which I also tried washing off but it kept leaving oil stains I can't afford a new backpack every few months so hopefully that's my decision.