Delta Cycle Airzound Very Loud Bike Horn Air Hooter | Rechargeable Bell Siren Alarm Super dB No batteries or cartridges required Volume control switch Clamp for mounting on 22 - 26mm handlebar Refills with any bike pump Refills with any bike pump--no batteries or cartridges required Super loud--up to 115 dB Volume control Lifetime warranty on manufacturing defects Air horn clamps to your bike's handlebar Colors may vary