UST See-Me 2.0 Water Activated 45 Lumen Strobe LED Light for Emergency, Camping, Hiking and Outdoor Survival DIMENSIONS: 5.5 L x 1.5 W and weighs 4 oz. with (2) AA batteries (not included) RELIABLE: Unbreakable LED bulb flashes 60 times per minute for up to 120 hours and never needs to be replaced DURABLE: Waterproof IPX7 which protects against water immersion up to 1 meter BE PREPARED:This light automatically activates when submerged in water or can manually be activated with an easy twist ON/OFF cap and is visible up to 3.1 miles on a dark,clear night exceeding the United States Coast Guard requirement of 1 nautical mile VERSATILITY: PFD clip, lanyard cord and hook and loop to ensure for a secure carry