Collar didn't even last a year before the collar split at the transition from the internal threads and the shoulder. Very thin at that spot and a bad design with no thread relief to move the stress away from thr load shoulder. Also, mating union is a bad design with a fixed shoulder versus a removable ring in a groove. This mean I have to cut apart all my plumbing buy a new union, flow sensor adapter, and additional pvc parts just to replace this threaded collar. Try harder circupool.....try harder. You should probably consider putting a decent engineer on a heavy duty collar to fix this.

These collars are perfect for making up a cap for acid cleaning the gen cells. Perfect fit

This is right one. Thanks