... back light, all use 4pcs AAA dry batteries. LED Bike Bicycle LightSpecification:-LED bulb:9 LED Ultra Bright White-Length: 97mm ... -Slide out the battery compartment-Replace batteriesApplications:.Bike lighting The Lamp can also be used as a flashlight. Idea for Home ... , camping, emergencies, etc Home, office, car, camping, emergencies, etc led bicycle light