Crosman Air Rifle 1763-026 High Pressure Polyurethane Oring (8 Pack) by Captain O-Ring [Benjamin Marauder .177.22.25] Replacement for Part No. 1763-026 Used in the valve body, gauge port, and fill adapter Polyurethane allows higher pressure and is more abrasion resistant in air guns that common black buna o-rings Contains eight (8) o-rings Manufactured and warrantied by Captain O-Ring LLC