This is the Sealife Flex-Connect Dual Tray with Mounting Screw

Features:

• Use the Dual Tray to add two lights or flashes, reducing shadowing and increasing stability
• Instantly add grips, lights, flashes and Flex Arms to the Dual Tray with just a “click!” and remove them with the push of a button
• Mounts to all cameras with a standard 1/4-20 tripod mount
• Includes mounting knob

Easily add two lights or flashes to your camera set

Use the Flex-Connect Dual Tray to mount two flashes or lights to your underwater camera for maximum brightness. Double your brightness, reduce shadowing and increase stability. Mounts all cameras with a standard 1/4-20 tripod mount.”