JMI EV1-C Dual-Speed Event Horizon Telescope Focuser - CassegrainJMI EV1 C Dual Speed Event Horizon Telescope Focuser Cassegrain Base A masterpiece of engineering and workmanship, the JMI Dual Speed Event Horizon Telescope Focuser is a low profile, friction drive focuser designed for the discriminating astronomer. The highly acclaimed Crayford design uses pressure on a metal drive shaft pressing against a machined metal drawtube which is held by bearings on the opposing side. This direct surface to surface drive