Features: Two tube rings make from metal,guide scope rings are suitable for small and medium size guiding telescopes,68mm compact finders guidescope kits for astrophotography for mounting a guide scope to main telescope The mounting bar has two M6 through-holes on both sides for easy adaption to rings. and three threaded through holes;the center hole has 0.25" 20 thread and the two largers holes on either side of center Solid metal guide scope rings for compact finderscope or guidescope with knurled metal screws. big screws with maximums grip allow easy use even with gloves The adjustment screws have inlays for avoiding unaesthetic scratches and pressure marks on the telescope while still ensuring reliable clamping The inner diameter of tube rings is 68mm for telescopes between 43 to 68mm tube diameter can be mounted adjustable Specifications: Material:Alloy Package Includes: 1Set Guiding Scope Rings with Plate note: Please allow 1-3cm error due to manual measurement. please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.