1: 20 LEDs, the total length of the light string is 2 meters2: Switch mode: two kinds of constant light and flashing3. Applicable to 98% of most models in the market. The hub diameter is from 13-32MM, including children's vehicles. When the battery box is used, you only need to tighten the screw on the battery box to hold the hub tightly, and the small hub of the folding car , You can use the rubber pad provided by the manufacturer to stick it in the bag ring.These LED bike lights for wheels from are the hottest new thing to hit SoCal and trend-setting cities across America. Fun basket stuffing for kids or Summer gifts for men who have everything, wife, son or daughter. Your bike will turn heads, 4,FOR SURE Each box lights 1 wheel so you can mix or match colors. Be safe Gain increased visibility from all directions so you and your loved ones are safer in low light conditions. Normal bike lights can only be seen from the front and back, leaving you vulnerable from the sides., your bike will STAND OUT from all angles, whether you are moving or not. Want even more ATTENTION? Switch from constant on to flashing mode. Get yours now easy installation