Skywatcher Auto-Focuser

• Hands-free D.C. focusing device, for accurate focusing, with the minimum
  of vibration.
• Dual speed push-button operation (fast & slow).
• Can
  be used with the following telescopes: Evostar models 90/102/120/150,
  Startravel models 80/102/120/150, Skyliner models 150/200/250/300 & Explorer models150/200/250/300

Customer review and notes which may be useful:

My review :

The Sky-Watcher auto focuser works well once attached but the instructions supplied are unhelpful and incomplete. The photo of the individual items in the kit fails to include the two different adaptors supplied for connecting the motor to the telescope focuser. One is a fat, silver, knurled nut (it arrived already attached to the motor in my kit , but it needs to be removed if not appropriate for your model of scope), the other is a black plastic tube with three tiny screws in it. You use one or the other depending on your scope.There is also a choice between two different attachment plates supplied. You only need to use one and discard the other. No mention of battery type is made but once you've installed the flat rectangular one, you won't be able to replace the battery compartment cover properly because it's so shabbily made. Instructions on how to remove the knob on telescope focuser aren't correct, either. The device does work, though, despite all this