This Handy Stepper Motor unit only operates with the 2-Inch Focuser Boss II electronic focuser. Its housing design allows for manual focus knob adjustments by merely turning the over-ride knob on the motor housing. It has an integrated temperature thermistor which permits temperature command via the Focuser Boss II digital system.

The HSM20 has 19,450 steps per inch.

This model fits 2-inch Feather Touch focusers as well as MPA Tele Vue, Takahashi Retrofits, and Micro Feather Touch. Telescope Focusers for Schmidt-Cassegrains telescopes.