SmallRig 2058 Super Clamp with 1/4" & 3/8" Thread (2pcs Pack)
It can open Max 40mm, and minimum 15mm rods.
Comes with 1/4"-20 and 3/8"-16 thread, can be mounted virtually anywhere
Compatibility:
Accessories with diameter 15mm-40mm
Package Includes:
2x Super Clamp 735