Ultra compact seat bags with zippered and exterior storage capabilitiesRail Wing system secures the Elementa SeatBag to saddle rails, even while removing itemsAdditional anti-slip cinch strap holds c02 or small tools in place reliably Interior zippered compartment designed to accomadate a single replacement tube and 2 small leversVelcro Strap18.3 c.i.BlackSmall (1-100 c.i.)