The Testar Helical Focuser for Finderscopes allows you to easily convert your straight-through Sky-Watcher finderscope into a proper guidescope, without the need to modify anything. All you need to do is unscrew the rear eyepiece section and replace it with this. The helical focuser is non-rotative, so your cables to not get twisted as you focus.
This is the only helical focuser on the market designed specifically for straight-through finder scopes that is compatible with Mini-sized guide cameras. There are others out there, but they will not allow you to reach focus - we've tested them!
Made of CNC-machined and hard-anodized aluminium, with a brass ring to securely clamp your camera.
Note: Compatible only with ZWO Mini cameras and QHY planetary/guide cameras which have a 1.25" diameter. Finderscope is not included.