Bicycle Parts Features Use 4pcs high quality LED Bicycle rear light, super bright bike rear rack light. With 2 modes,one is steady,one is flash. Use 2pcs AAA batteries,easy to replace. (Battery not included) Up to 60-80 hours Including bike reflector,improve safety. tool-less installation on the bicycle carrier, 100 meter visibility, Distance between 2 screws: Adjustable,from 50mm to 70mm is ok. Enjoy safety in rain, snow even thunderstorm extreme weather Advantages 1: Screws are removable,can fits for most kind bike carriers. Advantages 2: Bicycle rear light use 4pcs high quality led,very good for use as bike rack warning light. Advantages 3: This bicycle rear light use 2pcs AAA batteries to work ,easy to replace. Working time up to 60-80 hours. Advantages 4: Including one bicycle rear light and one bike reflector. Even your battery have no power,can ensure use it as bike warning light. Package include: 1*Bicycle rear light 2*Screws Warning:The batteries are not included The second choice:With strap mount on seat post We offer another mount way for customer,you can install the light on seat post. Service Policy Warranty Term: 1.