I have the same on for for 2x. There are awesome and made really well. I do find the Powermates and this T-ring to work very well together. Its a littel intimidating at first when you unscrew your beloved Powermate black coupler fitting to add this fitting but trust me . . . everyhting will be ok 🙂

* The Powermate unscrews in the middle

and separates the shinny side from black female half. You'll be exposing the lens in thhe shinney side so have a firm but careful grip, don't drop the baby 🙂

Awesome product

Fits nicely with M48 camera and helps with vignetting with Rasa

I’m very glad to have these installed! It’s a needed improvement. They simplify the collimation process. No more screwdriver!

Excellent mount, impressed

Awesome! Perfect fit! I installed it less than 5 minutes. Make sure to grease the threads on the allen screw before assembling the camera mount. I also used a machinist’s square to make sure the two pieces were square with each other. Everything went together like a charm.