The Arkel Waterproof Seat Bag is made of a four panel shell that is attached with reinforced Velcro straps under the seat. The waterproof pouch slides out in a second to keep bike tools and spare tube close by while making repairs. No zippers to operate. In addition to protecting the content, the shell compresses and stabilizes the pouch so that the whole bag attachment to the saddle is rock-solid. Everything stays dry in the worst deluge of rain or mud! Carrying a wallet and other essentials? Pull the pouch out and bring it safely along with you.