I have a TMB adapter for the Feather Touch Focuser. It will work on a TMB with the 3" focuser. This adapter threads onto the focuser tube of the TMB and allows the Feather Touch Focuser to be attached via 3 set screws. It is a CNC adapter of the same quality and material of the tube assembly. This was never used. Paid $100.00, make me an offer that is reasonable and it is yours.