HP Check Valve, Inlet/Discharge, 0.88 plunger units 55,000-60,000psi, 3.800-4.100 bar Used on all SL-V and SL-VI units with a button style poppet with a 15 to 60 horsepower rating. Kit includes valve seat, inlet and discharge poppets, poppet pin, compression spring & poppet retainer screw