Dealpeak Ultra Loud 5 Modes Cycling Horns Bike Bicycle Handlebar Ring Bell Cycle Horn Please noted the bike horn worked with 2 AAA batteries, The black button is main button to operate the horn.The red button changes sound only.Please find the black button at end of curly wire that attaches seprately to handlebar. Compatible with all bikes including road bikes. 5 kinds of sound effects.Extremely loud & clear sound. Worked with 2 AAA batteries (Battery NOT included) If you ride your bike on busy main roads, make sure people can hear you coming with this super loud electronic bike horn.