A ALSTAR Bahtinov Mask Focusing Mask (FM80mm) for Telescopes

This Bahtinov mask is designed for astronomical telescopes, fitting outer diameters from 85mm to 120mm. Made from 2mm thick laser-cut ABS or precision laser-cut enforced plexiglass, it ensures durability and precision focusing for both reflector and refractor telescopes. Securing screws are capped with soft plastic to prevent telescope damage, and the mask features a 3-post mounting system with non-scratching silicon sleeves for a secure, central grip without slippage. It simplifies focusing, even in challenging seeing conditions, by providing a mathematical approach for quick and easy optimal focus.