New York Toner Xeccon Mars 60 USB Linear Smart Brake Rear or Tail Bike Light 650mAh Battery Smart Linear Red Tail Brake Light with Strobe function. Very Compact and light weight, only 70g with built-in battery! Built-in USB rechargeable Lithium Polymer Battery. Smart Brake Feature: the light will be switched to high intensity brake mode automatically when stopped. Up to 6.5 hours of run time.