The Niterider Sentinel 250 Tail Light is a sound option to make yourself more visible to traffic in both day and nighttime conditions. With 7 different modes, you can choose the right setting for the conditions at hand to help you make it home safe. There are two flash modes, the brightest of which is Daylight Visible Flash that projects the full 250 lumens, allowing you to be seen day or night. There are two steady-beam modes: High, which maximizes visibility, and Group Ride Mode, which reduces brightness for times when you have other cyclists in tow. There are three Laser Lane modes which project bright laser lines onto the ground, creating a virtual lane for the rider that further improves visibility. An easy on/off seat post strap makes installation a breeze and lets you remove the tail light for charging, leaving the mount attached to the bike for convenience. A USB-rechargeable lithium-ion battery keeps things simple, and the charging cable is included.