... Electric horns include: Trumpet type and disc type, according to structure;12V and 24V, double and single wire type, according to ... of loudspeaker tube, diaphragm, winding, chassis and platinum contact, etc. It is a electromagnetic vibration phonic system. Disc type electric horn ... is composed of diaphragm, winding, chassis and platinum contact, etc. It is a electromagnetic vibration phonic system.