Aluminium Alloy Material: Made of anodizing aluminium; precision machined solid aluminum finder shoe base in matte black; for almost all viewfinder holders; for Witty 1 Tangent attachment etc; fits all lens barrel radii Easy to Install: Two large knurled thumbscrews makes it easy to install: Bases feature two large thumbscrew locks to secure your finder scope or reflex sight in place; even while wearing gloves; just put it on the optical tube and tighten the screws Multi-Function: There are two elongated holes on this base and a single countersunk hole for screws up to M5 in the middle; two screws are on the side of base; the distance between the center points of the screw holes is 24 to 41 mm The laser pointer holder is compatible with various sizes; accommodating a maximum diameter of 30mm and a minimum of 5mm;The inclusion of a 1/4-inch standard camera thread hole makes it compatible with most telescopes; including Celestron Sky-watcher Vixen and other models Multifunctional tool can be transformed into a sophisticated telescope viewfinder; making it an ideal companion for enhancing your stargazing experience with various accessories and taking it to the next level