Dakine ABS Vario 15L backpack cover. This durable cover works in conjunction with the ABS Avalanche Vario Base Unit (sold separately) and easily and securely zips onto the Base Unit with the help of the Base Unit's unique YKK zipper system. Thanks to the Cover's 15-liter size you have more than enough room for all of your avy gear, snacks, spare gloves and goggles, puffy, and other small essentials for a short backcountry tour. Base Unit's unique YKK zipper system. Cover only.