The Lezyne Zecto Drive Auto 80 rear light comes with a built in motion detector which will automatically turn the light on when you start & turn it off 3 minutes after you stop so you dont accidently run your battery down. The Zecto Drive Auto 80 has three ultra-bright LEDs. They can be used in 8 different modes including a super high-vis 80-lumen Daytime Flash mode. This low profile light is perfect for commuters or for road riders who want to keep going through the winter months. The Lezyne Zecto Drive Auto 80 is rechargeable via a micro-USB port & comes with Lezynes patented versatile 2-in-1 Clip-On System that can strap the light to handlebars or clips to loops on bags & clothing. MAX LUMENS: 80 WEIGHT: 47g RECHARGE TIME: 2.5hrs