Impulse is a versatile companion for a wide range of ambitious day tours, from all-day trail runs to alpine mountaineering and day hiking. The zippered main compartment opens wide at the top for easy access to clothing and larger items. Inside are four mesh pockets: one zippered pocket at the top, one pouch on each side of the bottom and a hydration pouch along the foam back. Tube ports on each side and elastic keepers on each shoulder strap accommodate left or right hydration-tube orientation . A small outer zippered pocket and three stretch mesh pouches provide plenty of quick-access external stowage. A lightly padded, double-layer base maintains lower load stability and enhances durability. External daisy chains and EXPED's exclusive Tool Blade combine to securely transport ice tools and other hardware. A removable compression cord with toggle adjustment compresses the load when necessary. Thermo-formed back panel and padded, contoured shoulder straps are comfortable and quick drying. Impulse 15 is sold with a lightweight waist strap; 20 and 30 liter versions with removeable, low-profile, padded hip belts, each with a small, zippered stretch pocket.