Impossible to find brand new genuine Spector set screw knobs. Spector sells a set of four for a whopping $60! These are for solid pot shafts only. These are used on the USA and some Euro models. $30 for a set of four shipped anywhere in the USA. PM your email and I'll send a Paypal invoice. Check out my stellar TB feedback! Get rid of those funky aftermarket skull knobs and return your bass to stock appearance!