The cateye loop 2 rc rear light is a superbly versatile light for whenever and wherever you need it it has two modes to choose form to ensure visibility when riding at the darker times of the day if you choose flashing mode your battery will last up to 10 hours and if you choose constant more your battery life will last up to 2 hours if you choose the rechargeable battery version of this rear light this cateye rear light is small light weight powerful and affordable it is import