... -102-2,12V/24V,JGK-505valve with aluminum coil/JGK-502 valve with copper coil,Dual tone electric air horn One pair ... -2,12V/24V,JGK-505valve(with aluminum coil)or JGK-502 valve(with copper coil) raised base cover,Dual tone electric air ... good, not influenced by the vibration, low temperature, high temperature, voltage change affects4, permanent keep users set voice5, installation simple operation ...