On the trail or on the water, the waterproof UST See-Me 1.0 LED Lights ensure you can be quickly located in an emergency. An ideal personal locator light, they are visible from 2.7-3.4 miles on a dark, clear night and are great for backpacks, boats, PFDs and more. Approved by the US Coast Guard, the Steady-On Light (20 lumens) runs for up to 17 hours and the Strobe Light (28 lumens) runs for up to 44 hours each on 2 AAA batteries (not included). The lifetime LED bulb never needs to be replaced.