The JMI EV-3CM is a fine motorized rack-and-pinion focuser designed to work with Cassegrain telescopes from 6" to 16" diameter. It is a 2" black-anodized aluminum focuser equipped with knurled knobs, standard brass ring and reducer to accept 1.25" eyepieces. The EV-3CM can support up to 4 pounds. It features manual control for focusing, which is over 1 1/2 times finer than any other products of its class. This motorized version comes with the SCT threaded output adapter to allow use of standard (SCT and Mak-Cas) equipment. The hand unit has an electronic brake to stop the motor during usage. Some older Meade LX200 telescopes do not supply enough power to run the motor on the low setting.