About this item ? ? M2 Bike rear light is outstanding for compact size(only 3.5cm of diameter), excellent autonomy(up to 90 hours on one charge) and great versatility(2 mounts for saddle and seatpost, also can be used as dog light, backpack light, helmet light, wheelchair light ). ? 5 Unique Lighting Modes – Steady Mode(6 hours), Strobe Mode(15 hours), Meteor Mode(23 hours), Taichi Mode(27 hours) and Marathon Mode(90 hours), ideal for long-distance or team cycling on & off road. Single press to turn on and choose mode, long press to turn off. When you turn it on next time, it’s on the last mode you used. ? IPX5 Waterproof & USB-C Rechargeable – Well sealed to protect the bicycle rear light from dust and water. Just charge it fully with any USB A – USB C cable in 2 hours and it lasts for weeks, or even months. ? 2 Brackets for Saddle & Seatpost of Road, MTB, Hybrid and Commuting Bicycle – Quick release and stable design, no worries about lost it on bumpy roads, and you can leave the mount on your bicycle and take the bicycle tail light with you in your pocket. ATTENTION: Rotate until you hear a “click” sound to secure the light to the mount. To remove it from the bracket, just reverse the rotation. ? Packing information: 1 x bike back light, 2 x mounts, 1 x charging cable and 1 x user manual.