**Grooved Finderscope Base** The grooved finderscope base is suitable for various round main mirror tubes, clamps, dovetail plates, etc. It has a 1/4 screw hole and an M4 through - hole. It is made of aluminum alloy. Its codes/numbers are XY - 230729 Red A and XY - 230729 Black B, with a weight of 49 grams. It features an oxidized surface layer, a 1/4 screw hole, and an M4 through - hole. And it is suitable for various round main mirror tubes, clamps, dovetail plates, etc. The bottom is designed with a groove, which is more suitable for the main mirror of a cylindrical telescope Price is the price of a product, not the combination of black and red.