1.This 360º Articulation Double Ball Adapter with clamp is designed for photography studio video shooting. Crab clamp maximum open distance is 54mm; Best loads is 2kgs/2.5 lb 2.Multifunction: the maximum open distance of the clamp is 54mm, which can help you fix the accessories on 15mm rods, for DJI Freely Movi 25mm and 30mm rods, plate, shoulder rig, bike handles, and so on. 3.The ballhead mount clamp is made of aluminum alloy and stainless steel which is very well built and is very longlasting. It is a perfect and study ballhead mount for people who love making videos. 4.Standard 1/4' and 3/8' female thread: 1/4' and 3/8' female thread on the backside of clamp help you to mount a small camera, monitor, LED video light, microphone, speedlite, and more. 5.Flexibility: you can remove the ballhead arm form the clamp and install a different type of arm with a standard 1/4' male screw; the ballhead can be also used on something else because of the standard 1/4' male screws at both ends.