Made In USA! Made for the Crosman models 150 & 157 CO2 pistols. Material: Urethane offers superior strength, tear and abrasion resistance. Our O Rings are handled by USPS Ground Advantage in a box with tracking number, not in an envelope that can be damaged by postal equipment, delaying your order or losing your o rings. One (1) basic O-Ring seal kit, for the Crosman models 150 & 157 CO2 pistols. Five (5) seals are included in this kit: One (1) tube cap, URETHANE o-ring seal. One (1) piercing body, (front) o-ring seal. One (1) exhaust valve, o-ring seal. One (1) bolt, o-ring seal. One (1) extra bolt, o-ring seal. Urethane offers superior strength, tear and abrasion resistance.