The mounting bar has two M6 through-holes on both sides for easy adaption to rings. Three threaded through-holes: the center hole has inch-20 threads and the two larger holes on either side of center have M8 x 1.25 threads. Synta-style dovetail bar - Accepts all sights designed to fit a standard Picatinny rail. Fits into standard finder shoes by , GSO, , , . Fits the dovetail mounting base on most telescopes. Machined of high quality aluminum and anodized black, durable for long time use. Colour:black Material:Metal Package Contents: 1 x dovetail board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.