SN4 SN70 O-ring kit + LB3500 + Bumper BB0018 + BB0059SN4 & SN70 O-ring kit + Washer Firing Valve Seal LB3500 + Bumper BB0018 + BB0059Available Qty: 3 Post navigation SN4 O-ring kit + LB3500 + bumper BB0018 Senco BA0103 Valve