The Hydralight flashlight uses the latest fuel cell technology to run on water instead of batteries! Simply twist off the bottom, remove fuel cell, submerge in water for 10-12 seconds, vigorously shake out excess water and you're ready to go! The fuel cell can provide up to 100 continuous hours of lights with a single water dip. Hydralight has a rubberized armor coating that is rugged and built to last. Perfect for lighting on camping trips, makes a great emergency tool for cars or keep in the garage or under the sink for at-home use. The Hydralight has a 25-year shelf life. Also works as a hands-free lantern and can be upright on tables. Flashlight measures 10 from end to end. Comes packaged inside a hanging clamshell measuring 7.5" x 14.25.