Safety Bright 6" or 4" Scuba Diving Cyalume Chemical Lightstick Light Stick Glow Stick Dive Diver Cyalume Chemical glow safety lightstick for Diving GREAT FOR EMERGENCIES - HALLOWEEN - CAMPING - SAFETY, ETC The 4" lightstick is great attached to a snorkel - For overwater or underwater use Non-toxic - Night marker or emergency - No heat or sparks when lit Completely waterproof - Lasts up to 6 hours - With hook