I don’t know if there is job I hate more than installing a DRO. Can’t quite pinpoint why, maybe because its just such freaking fidgety futzabout.   This is my third, this time using a Made in China DRO (ho hum).  Previous efforts were with a Mitutoyo and a Newall.  Newall is by far the best,  but I just didn’t want to spend the money on this one