Each Ultimate Trail Pack has two detachable panniers Sectioned compartments help maintain load balance and reduce shifting Panniers detach allowing the harness to be used as a standalone walking harness Made of 600D PU ripstop nylon with 210D PU nylon lining Reflective piping keeps your pet visible at night Nickel plated D-ring for leash attachment Grommeted holes at the bottom of the panniers keep them sand and debris free Durable and machine washable Volume held by the trail packs: Large = 7 Litres per pannier / 14 Litres total