This is the XS Scuba PLUS Lights BCD Lighting System Features: Public Safety Team Leaders can keep track of their divers in the water Having light surrounding your body makes it easier to locate and use your accessory equipment The PLUS System, found exclusively on XS Scuba BCs, is a string of micro-LED lights, sealed in a solid 4mm transparent casing. The casing is threaded through a series of small elastic loops that line the perimeter of the SeaBlazer and Phantom BCs. The PLUS System has many applications in the categories of safety, practicality and fun.