Bike LED light is waterproof, safer in water fog when riding in the rain. May you be seen and heard at night when riding, enables you a safer riding | Four switches control 4 tone of police whistle, this bicycle horn bell powered by - 2 AA batteries (No batteries in) | Easy to install and remove without tool. Attaches easily to most bicycle, suitable handlebar diameter: 24mm/1inch | Fun purpose: your children can use this for fun purpose like playing police pretend play games that will be a joy for them with loud and loud sounds trumpet cycling horn bell siren | Wide application: our bike police LED light can be applied for a wide range of activities: road biking, city commuting, hybrid bikes, kids bikes etc.; And it is very suitable for people who usually rides bikes at night