k grips the telescope tube gently and firmly with three metal poles. These metal poles come with scratch resistant silicone covers to protect the surface of your telescope. This prevents slippage while keeping the mask perfectly centered.
Wide range of applications: works with all types of telescopes, mirrors, refractors, for Dobsonian, for Mak Cas and for SCT, all you have to do is measure your telescope tube size and choose the size appropriate mask.
Post-Installation and Lightweight Design: With this 3-post mount, the mask stays centered while adapting to a wider range of telescopes. The bahtinov focusing mask for telescopes is lightweight so as not to upset the balance of the telescope.
Function of Bahtinov Masks: The mask takes the guesswork out of focusing and even overcomes viewing conditions to get your telescope in the best focus quickly and easily.
Applicable size: The outer diameter of the bahtinov mask supports the telescope objective lens within the range of 100-140mm (there is an error of 1-2mm in manual measurement).
Specification：100% brand new and high quality
Note:
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