This is the Apeks Surelock Weight System Attachment Features: Includes necessary attachment hardware plus spares. May be used without the SureLock(TM) Weight System to spread the weight of the cylinders over the hips. 3 different grommet settings allow for proper positioning of the SureLock(TM) weight pockets. 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 unique accessory allows you to mount the SureLock(TM) Weight System (Patented) directly to the back plate.