This flange adapter is a requisite for attaching a clamping plate to your GM 3000 Mount. This means that it is also a requisite for attaching a normal telescope to the GM 3000 mount, as the clamping plate is an essential component of that process. While it is theoretically possible to attach a plate directly to the mount, the plates low profile makes this a very bad idea, and it is recommended you use a plate with this adapter to give the knobs proper clearance.