The large quick release base is an accessory mount, used in conjunction with a large camera swivel and large mounting base, allows you to quickly and easily remove your camera system from the swivel mount on the scooter hull. Another benefit is it allows for easier mounting installation of the camera to your scooter hull, by allowing the pieces to be individually bench-mounted to the camera and scooter respectively, then easily attached at the dive site, or in-water.
This is the portion which mounts to your camera, and is the extra-wide version for super large DSLR rigs and pro-video systems. It measures 12 inches across and 4 wide.
*Note this must be mounted to a large camera swivel, and used with the quick-release mounting base of your choice (not included.)