This is the Scubapro Hydros Pro Ninja Pocket

Features:

• Attaches to multi-mount matrix points on your HYDROS PRO BCD.
• Deploys quickly when needed, rolls up out the way when not needed.
• Ideal for storing instructor slates, dive lights, marker buoys, spare masks or compact cameras.
• Includes the pocket, the accessory mount plate, and two stainless steel screws.

When you'd like the option of additional stowage for occasionally carrying accessories on your HYDROS PRO, the Ninja accessory pocket is the perfect solution.