The moon shield x auto rear light is an eye catching light with features that help it stand out from the rest featuring a super bright cree xp e red led and with clever optics the light can be seen from a mile off the light is usb rechargeable which makes it super convenient to use when riding to and from work if you run out of battery on the way into work then you are able to simply plug your light in to a usb port via the charging cable supplied and leave for 2 hours programmed with 5