Package Includes - 72 reflective clips that fit most round spoke bikes. Material - The bicycle spoke reflectors are made of ABS material and reflective stickers for durability and long life. Easy to use - the reflex sticks are quick and easy to assemble, without tools, slide the spoke reflector onto the spokes and pull it out to release the spoke when you no longer need it. Function of the product - used in the bicycle spokes, give a strong reflection under the light irradiation. Increases safety by increasing visibility at night and in bad weather it is a very good decorative ornament and night, riding a bike at night can effectively prevent accidents (external light source required). Note - these are reflective strips, could not light itself, could not light up when driving in the dark with no lights on.