- optics train
Bought to replace a similar adapter that had only one tightening screw. This adapter has two, therefore not only tightens but does so uniformly so there is no 'wobble' in my optics train.
I'm quite impressed. It's light weight unlike some others -- important considering the weight of some eyepieces. The internal 2" threads for filters means you don't have to duplicate filters in both 2" and 1 1/4" sizes. And having "T" threads at the eyepiece end allows it to replace a camera adapter in my eyepiece and adapter case.