Televue Focus mate Driver FDF2004, (for Televue TVNP-127is) permits vibration-free, variable-speed, electronic motor control of the Televue 10:1 Focusmate Fine Focus Accessory through a hand controller or computer control . A tap on the button permits vibration-free focusing in steps as small as approximately 0.0005" or download TVFocusPlus. Switching between manual focus and motor focus is easily done with a unique quick disconnect that doesn't require tools. TeleVue produces a wide variety of refractor telescopes, telescope mounts, and telescope accessories for all user levels. Tele Vue products deliver excellent quality at a reasonable price. As a result Televue Telescope Accessories are ranked very highly and are used by professionals and enthusiasts the world over. Also, our store carries a wide selection of different products made by TeleVue, such as TeleVue Telescopes, Tele Vue Tripods and many more .