Used in addition to approved lifejacket lights. 2 flashing LED Lights (pair) illuminate the inflated lifejacket bladder to increase visibility and aid location. The Lum On Light is water activated and waterproof (IP68).It uses the inflated lifejacket bladder as diffuser to increase visibility.Compact design.Attaches and integrates only in lifejackets with separate bladder and cover construction. (All Spinlock lifejackets have been tested and approved for use with the Spinlock Lume-On. If fitting to other of brands of lifejacket, it is the users responsibility to check the compatibility with the lifejacket Manufacturer.) Sticks directly to underside of inflatable chamber.Standard feature on Deckvest 5D (2016 onwards)