type-A: A set of 12v-24v universal-single horn-general, type-B: a set of dog barking horns + modified wiring harness + button switch-single horn-universal, type-C: horn + special car plug-order note model-single horn-general Note: Be sure to disassemble when buying to see the voltage model on the original car horn is being purchased. Different voltages may cause the horn to sound low or not sound.