Precision Focusing Mask for Telescopes, Aluminum Alloy Pattern Focusing Aid for 84mm to 115mm Outer Diameter Tubes, Works With Reflectors Refractors Dobsonians SCTs, Quick Mounting and Easy Adjustment for Clearer Stars

Aluminum Focusing Mask for 84-115 mm Telescope Tubes
✔️ Aluminum alloy, 1mm thick; 3-post mounting keeps mask centered.

This lightweight focusing mask is designed for a range of telescope types, including reflectors, refractors, Dobsonians, Mak-Cass and SCTs. It works with outer diameter tubes from 84 mm to 115 mm, and it’s ideal for field use or at the eyepiece, helping you lock in crisp stars quickly. Pack size: 1 x Telescope Focusing Mask.

✅ Fits outer diameter 84-115 mm (3.3-4.5 in) telescope tubes.
✅ Weight about 57 g (2 oz); brass, aluminum, rubber construction.
✅ Aluminum 1 mm thick keeps it lightweight and durable.
✅ Three metal posts with 3 bolts keep the mask centered and secure.
✅ Works across reflectors, refractors, Dobsonians, Mak-Cass and SCTs.
✅ Pack: 1 x Telescope Focusing Mask.

💡 What is a telescope focusing mask used for in astronomy and how does it help you get precise focus?

It helps you confirm focus quickly by creating a repeatable visual cue. This handy device reduces guesswork and speeds up focusing across telescope types. - It diffracts light into a three-starburst pattern that aligns at sharp focus. - Works with 84-115 mm outer diameter tubes on reflectors, refractors, Dobsonians, Mak-Cass and SCTs. - Lightweight aluminum alloy construction with three-post mounting keeps balance and alignment. - Easy to mount with 3 bolts for quick field setup. ✝️