SecureFit 1/2 inch Extender

Finally got my back focus perfect for my reducer; stacking three of these was easy and rock solid. The threads are smooth and they don't add any slop to the imaging train.

I needed just a bit more spacing to get the back focus right, and this extender threaded on perfectly with no wobble. It's nice that they stack too, in case I need to add more later.

Stacking three of these got my flat frame correction dialed in perfectly. The threads are buttery smooth, no wobble or tilt at all.