Description: Fits for Car Truck Train SUV VAN Boat Motorcycle. Single trumpet air train horn with glistening black finishing. 150 decibels sound, super loud. Small size but powerful volume and tuned train horn sound. Easy to installation only need to simply mounted on your air compressor. Great sound quality, extremely stable frequency. Long service life, reliable working performance. Specification: Color: Chroming Material: Plastic + Iron Decibel: 150dB Voltage: 12V/24V Overall Size: Approx. 445x100x95mm/17.5x3.9x3.7inch Caliber: Approx. 95mm/3.7inch Current: 5A Package Includes: 1 Piece Single Trumpet 2 Pieces Brackets 4 Pieces Screws Note: Professional installation is highly recommended if you have any difficult in installation The positive and negative poles of the power supply are respectively connected with the two wires on the solenoid valve(no positive or negative points) The air tap on the solenoid valve is connected to the gas source of the vehicle(make sure no air leak)