Water activated automatic safety strobe light for use in poor visibility to keep contact with you buddy or trainee, manufactured from ABS Styrene, so will never rust even with regular intense immersion in sea water. Supplied complete with corrosion resistant stainless steel safety pin style attachment to allow safe, secure and convenient positioning. Extremely lightweight at only 27 Grammes and a neat compact size of just 89mm in overall length and 18mm in diameter. Flashes bright green every approximately 130 times per minute, depth rated to 100 metres with an incredible 750 hours burn time. Turns off automatically when dry.