Farpoint Bahtinov Focus Mask — 67mm DSLR LensBahtinov focus mask for camera lenses with 67mm filter threads. Snaps into the threads of an inexpensive 67mm UV filter (one time install). From there, screw the filter onto your lens for a focus check, then unscrew it to shoot quick and tool free. Made in our own shop in the USA American materials, American machinery, by Americans. Works with any DSLR or mirrorless camera lens that takes a 67mm front filter. UV filter sold separately any inexpensive