ADVANCED DESIGN:USB rechargeable front and rear lights, built-in 2000mAh lithium battery for headlight and built-in 330mAh lithium battery for taillight. FOUR LIGHT MODE OPTIONS:HEADLIGHT AND TAILLIGHT HAVE PUSH-PRESS SWITCH WITH FOUR DIFFERENT LIGHTING MODES TO DEPEND ON YOUR PREFERENCES.INCLUDE FULL BRIGHTNESS, HALF BRIGHTNESS, FAST FLASHING AND SLOW FLASHING. EASY INSTALLATION:THE HEADLIGHT IS EQUIPPED WITH A MOUNTING BRACKET THAT CAN BE EASILY ATTACHED TO THE HANDLEBAR.THE HEADLIGHT AND TAILLIGHT SILICONE MOUNTING STRAPS FEATURE FOUR OPENINGS that fit snugly around most size seatposts.HEADLIGHT AND TAILLIGHT CAN EASILY DETACH AND ATTACH, and no tools are required. MULTI-FUNCTION:THIS BICYCLE LIGHT SET IS VERSATILE enough for cycling, hiking, camping or any outdoor activities and can be used as an emergency flashlight.This is great for night riding or places where visibility and safety are important.So just start your next adventure with us.