... -2,12V/24V,JGK-505valve with aluminum coil/JGK-502 valve with copper coil,Dual tone electric air horn One pair JGY-102-2 ... ,12V/24V,JGK-505valve(with aluminum coil)or ... JGK-502 valve(with copper coil) raised base cover,Dual tone electric air hornProduct features: 1, horn sound quality good, frequency extremely stable2 ...