These split and hinged optical tube mounting rings are made of cast-aluminum, feature quick release, hinged clamp knobs and felt lining. Designed for use with GSO mounts, they also fit with some other brands of mounts as well.
Inside diameter (ID) is listed. Choose the size that matches the outside diameter of your telescope tube. If OD of the telescope is a little smaller than ID of the rings that you can shim the inside of rings with extra felt.
TR300-Telescope tube rings, 90mm ID.
TR380-Telescope tube rings, 116mm ID.
TR280-Telescope tube rings, 136mm ID.
TR500-Telescope tube rings, 176mm ID.
TR600-Telescope tube rings, 230mm ID.
TR800-Telescope tube rings, 303mm ID.
TR900-Telescope tube rings, 356mm ID.
TR90-Telescope tube rings CNC made, 90mm ID.
TR115-Telescope tube rings CNC made, 115mm ID.