Hornit Portable Waterproof 2-Mode Cycling Bicycle Bike Electronic Bell - Black (2 x AAA)
Can keep the drivers alert; With two modes: 140 decibels (special sound) / 130 decibels (ticking); Separate button switch for your convenience; Easy to install; 2 x AAA batteries with 6~12 month's normal lifespan; IP44 waterproof