Please report back with your results. I tried my collar in two different lights, one a Z1, and both times my “after” lux was about 30% lower than the “before” measurement. Obviously I aligned it incorrectly since I have no idea what I’m doing lol. But the led looked well centered to me before I held the collar in place with hot glue. The beam looked noticeably dimmer after adding the collar, but otherwise similar in profile.