Up for sale is a set of telescope tube rings in used condition. They are 4-1/4 inch diameter when fully clamped and 4-1/2 inch diameter when using maximum clamping screw open length. They are made of 1/2 inch wide steel strips with aluminum bases that are 5/8 inch by 3-1/4 inch and flat on the bottom. Each base has two holes drilled through and tapped for #6-32 machine screws.
Filed under: Eyepieces & Accessories