Spare base pate / flange / adapter for GSO refractor focusers. Should fit almost all GSO single speed, standard dual speed, and linear bearing dual speed refractor Crayford focusers. Before purchase, please remove the current base plate on your telescope and carefully measure the inside diameter of the focuser body to ensure that it is at least 73.5mm (2.89") or larger.
Please note that this item will NOT work with GSO's reflector, RC or SCT focusers or with any other non-GSO focuser. Meant only for use with GSO's refractor focusers that usually come with an 86.4mm, 96.6mm, or 112.5mm base plate.
To change the base plate on your GSO refractor focuser, simply remove the rotation lock screw, unscrew the 3 holding set screws, remove the old base plate, and attach the new base plate in its place. This requires a 2mm or 5/64" allen key (not included). Note that you will have to carefully adjust the tension on the set screws to ensure that the new base plate is smoothly rotatable. We also strongly recommend the use of removable (Blue) Loc-Tite to lock the set screws in place.
Weight = 5.1oz.; Telescope side outside diameter = 86.4mm (3.40"); Focuser side outside diameter = 73.5mm (2.89"); Total length = 40.5mm (1.59").