Beretta Optima-ChokeA(R) HP tubes stand up to the heat of competition. Manufactured from high strength steel and finished in a nickel-alloy coating, these chokes guarantee significant corrosion resistance and have the ability to withstand the rigors of steel shot. Optima-ChokeA(R) HP tubes are fully interchangeable on all Beretta barrels that are threaded for Optima-ChokeA(R) HP. Fits: Beretta A400 Xtreme, A400 Xplor, A400 Xcel, 690, 692, DT11, A300 Xtrema, SV10 Beretta suggest that - when using Steel Shot - you only use choke tubes marked with the SP (Steel Proof) identification on the side and that you use the most open choke system possible - i.e. Cylinder / Improved Mfg: Beretta Usa