Feather Touch 2.0" Dia Dual Speed 0.8" DTT, Brake, CRing (aka 'Shorty')
Starlight Instruments 2" Series...
In general, 2.0" Feather Touch Focusers can be used on refractor-style telescopes, they can also be used with Newtonians in certain situations depending on where the focal point resides.
Basic Componants of the Feather Touch 2.0 inch Diameter Focuser In our standard model, the base of the adapter is not threaded, instead it uses a 2.7" flange type connector. A base-adapter or tube adapter ring (TAR) is required in all cases for installing the focuser onto your telescope. Optional mounting base adapters are available for installing the focuser on catadioptric rear cells as well as on reflector optical tubes and truss-tube Dobsonian secondary mirror cages.
There are coarse and fine focus knobs with an approximate reduction ratio of 10:1 for unrivaled accuracy and repeatability. Each revolution of the fine focus knob results in a mere 0.070 inches of drawtube travel, making critical focus effortless. Fine focus repeatability is on the order of <0.0005 inches.