From Manufacturer
Dock your handheld 3-axis gimbal system when it's not in use with this Universal Docking Bracket from Proaim. The bracket features a 5/8" female pin, a top male 5/8" pin, and two extendable arms with hooks to hold your gimbal or ring. The arms feature two hooks on the end that can accommodate standard gimbal handle tubes with a 30mm diameter.
The arms extend from 9.4 to 14.2" wide and 15 to 19.7" long to accommodate different size rigs that weigh up to 66 lb. You can mount your gimbal on a cart or even a C-stand that can adjust to your height so you can easily dock, adjust, and balance the rig. The bracket also features a 5/8" male pin on top, so you can still use the pin to mount your rig's gimbal bracket or other items with a 5/8" mount.