Mounts between tower shelf and rotator. Discontinued GC-038 Mast Clamp G450A/800SA/800DXA/1000DXAFor mast 1.5 to 2.5 inches Not in stock GC-048 Mast Clamp G2800DXFor mast 1.875 to 2.5 inches Not in stock GL-33 Mast adjustment plate. Not in stock GS-065 Thrust Bearing 1.5-2.5 inches....