This is the Sealife Flex-Connect Y-S Adapter Adapts Y-S light mounts to Flex-Connect

Connect underwater lights and flashes using a Y-S mount

The Flex-Connect Y-S Adapter easily connects any underwater light or flash using a Y-S mount to Flex-Connect grips, trays, arms, cold shoe mount, and other accessories – with no need to worry about compatibility issues. The Y-S Adapter rotates on its base left and right, and has up and down directional control by angling the light on the mount.
Easily expand with Flex-Connect accessories
Quickly and easily expand your underwater camera with Flex-Connect – add grips, Flex Arms, trays and other accessories with just a “click!” Flex-Connect allows you to transform your camera set from compact to full-featured in just seconds, providing a quick way to adjust to any dive environment.”