This is a very premium anodized aluminum adapter; this adapter has a standard SCT male thread means 2 inch or 24 TPI on one side to connect to the female SCT thread; the other side has a standard 42mm or M42 x 0.75 female thread
All metal construction and anodizing aluminium process for long time use
Converts an M42X0.75 male thread to a SCT male thread means 2 inch; 24 TPI
This clever accessory makes it possible to have a dual focal ratio instrument; without sacrificing image quality
This combination focal reducer and field corrector lens accessory works with all Celestron 5 inch; 6 inch; 8 inch; 9.25 inch; 11 inch and 14 inch Schmidt-Cassegrain telescopes