As you look around my equipment... PMG keeps popping up. From the base plates of my cameras... Ball Head in my studio and now my Wedding/ Social Event Rig... So this attaches to your Boomerang Rig I have a Mk1/ V1 and this still attaches, just fine. It is a 1/4" stud adapter. It is meant to take NEW/ NEXT generation lightweight heads and mount them. Whole thing fits VERY well, even with a V1.1 or however they refer to my Boomerang system. It couples JUST fine with what I have and I can see... How to use this. These guys have it together and it is WHY I remain a customer. I started because they are LOCAL. I stay with because the the stuff is intuitive and it WORKS. I bought this because I KNOW I am going to get the "next gen" GODOX/ Flashpoint, but I can throw an old-school flashgun on this and get serious reach. That extra 5" helps to BOUNCE light in a high ceiling. I can think of a LOT to do with this piece.
Absolutely crucial if using a ful frame sensor camera in conjunction with anything wider than. 17-35mm lens. Great stability. I really appreciate that the top of the stem was machine with a flat side so that the light source will lock on without spinning around when in use.