Sherline's P/N 3700 rotary table comes with a P/N 37090 threaded adapter to allow you to attach standard Sherline chucks which have a 3/4-16 thread in the back. Owners of other brand lathes may have chucks that have a 3/8-24 thread in the back. This adapter screws into the center hole of the Sherline rotary table with the 3/8-16 end and works just like the standard adapter except that the other end is threaded to accept a chuck with a 3/8-24 thread.