WATER & SHOCK PROOF， lt Aircraft grade aluminum & rubber seals allows for protection from shocks， drops， and rainy days（IPX4）.Easy operation:The bicycle tail light charges from your computer or any device with a USB port. This Bike Light Only takes 2 hours to fully charge. Just press the lens to power on - 3 modes: High (3hrs run time)， Low (6hrs run time)， Strobe (50hrs run time).Safe and dependable，The tail lights will always alert drivers of your presence by grabbing their attention with glaring red LEDs. See and be seen from miles away.Easy installation: no tools required，Strap on anywhere in seconds and remove in seconds. Universal Fit For anything you can think of; Bicycles， Strollers， Dog leash， Hats， Helmets， Backpacks。Sale support:If you aren't happy with the bicycle tail light for ANY reason within 30 days of purchase， let us know and you get your money back!