This is a high quality slow-motion control knob from GSO for manual control of your mount's RA or Dec axis. It is approx. 1.14" (29mm) long with a large round hand knob 1.57" (40mm) in diameter. Weight = 1.3oz / 37g. Sold individually.
The end shaft has a 0.31" (8mm) bore. If your Antares, Celestron, GSO, Orion, Vixen or other mount has a stalk for slow motion control on either axis, and if you prefer to use shorter knobs instead of the longer stalks, then you can replace it with this knob to control the slow motion function. Just remove the existing stalk, slide thisknob on to the slow motion shaft, tighten the locking screw (requires 2mm or 5/64" allen wrench which is not included) and you are good to go.
Be sure to measure the diameter of your mount's shaft before you order this item. Many mounts have a smaller 6mm shaft, and this item will not work with those.
Important note for GSO SkyView / AstroTech Voyager Alt-Az mount owners: GSO has made two versions of this mount - one with a 6mm diameter shaft for the slow motion cable/knob and another with an 8mm diameter shaft. This knob is meant only for mounts with an 8mm diameter shaft. It will not work with the mounts that use the smaller 6mm shaft. So again, please measure before ordering.