This is a hydration pack, the same type used by the US military. It can be attached to a backpack. Both the cover and the main body are brand new and unused. To be honest, I'm not sure how to price it, so please let me know your desired price in the comments. - Color: Coyote Brown - Design: Slim design - Function: Hydration pack - Attachment method: Attaches to a backpack - Hose: Includes a drinking hose Thank you for looking.