Review on M48X0.75 Extension Tube Kit For Astromania Astronomical 2 - 5Mm 8Mm 10Mm 20Mm 30Mm Lengths On Both Sides by Aaron Vazquez

Threads are clean and parts glide smoothly when screwing/unscrewing. black anodized finish is uniform and fully coated. Baader Planetarium MPCC Mark III has slight resistance in threads when attaching extension tubes, but it works.The only suggestion for improvement, or an upgraded version, would be a matte finish on the inner surfaces. I doubt it would make a huge difference as the threads already break up the reflections quite a bit. I suppose one could coat the inside with matte black Krylon and perform a contrast comparison, but I'll leave that as an exercise for another reviewer.