This focuser I believe was originally on a FLT110.
It has a 100mm drawtube.
Rack and pinion with 10:1 fine control
It also has a rotating collar with calibration scale ( the gold and silver part )
the adapter has a threaded approx 138mm It currently has a sleeve with holes thru the threaded part which can be removed and used as threaded again.
The smaller end is approx 118mm threaded which goes onto the body.
The travel is 110mm or 4.25 inches.
only selling as no longer required.