Confirmed on these tables:

YAMAHA P-350 Turntable

YAMAHA P-450 Turntable

YAMAHA P-550 Turntable

YAMAHA P-650 Turntable

YAMAHA P-750 Turntable

YAMAHA P-751 Turntable

YAMAHA P-850 Turntable

YAMAHA P-950 Turntable

Your N.O.S. headshell kit includes all necessary mounting hardware pictured including the clamp down bar, Teflon washers, Allen wrench, and screws that are almost 3/4" long for any cartridge requirement specifically some legacy Shure and Empire pickups but yes they will be unnecessarily long for most cartridges as these screws are the only non-ferrous type we can source that fit the cross bar threads.