This is the Apeks Surelock Weight System, 10Lb

Features:

• Bolts directly to the WTX Harness
• Able to mount to the back plate with use of SureLockTM attachments
• Includes necessary attachment hardware plus spares
• 2 stainless adjustable D-rings on the outside of each pocket
• Features the SureLockTM (patented) mechanical weight release buckles which prevent weights from releasing until you want them to
• Each pocket holds up to 10 lbs (4.5kg) of lead
• Includes attachment grommets to mount your choice of Aqua Lung knives

The WTX and WTX-D Series is a selection of harnesses, buoyancy cells and accessories which offer unparalleled versatility due to the modular nature of the whole system. Each component can be configured into a highly technical rig for those trained to push the limits, or scaled down to make a travel friendly set up suitable for any diver.

This popular accessory is ideal when it becomes necessary to add additional weight to your rig. Using the included hardware, they may be bolted to the WTX harness or to the SureLockTM Attachments. SureLockTM is the best mechanical weight release system in the industry today. A simple click is all that is needed to engage the weights and a simple pull on the handle to release them. "