Solomark Bahtinov Focus Mask for Telescopes 140mm-Suitable for 140mm Diameter Telescope
Bahtinov focus mask for telescope 140mm
Masks now feature 3 holes which can be attached with 3 screws to prevent the mask from falling all the way to the ground
It will take less than 1 minute to achieve perfect focus with your new mask and will mean you spend more time imaging photons rather than focusing them
Light weight so you wont upset the balance on your scope.