Item P N Qty. Description Type 1 12 40ea O-Ring big for Z2S22 2 30ea O-Ring samll for Z2S22 (The above items are used in Double return check valve. Type: Z2S22-1-5X) 1 13 40ea O-Ring big for 4WEH22 2 20ea O-Ring samll for 4WEH22 (The above items are used in 4 3 Directional valve. Type: 4WEH22G7X *****)