Description: UNIVERSAL APPLICATION: This Generic Loud 4 Trumpet Train Air Speaker is suitable for all types of vehicles equipped with air supply units, making it a versatile addition to your vehicle.Electrical requirements: The operating current of the control relay must be greater than 10A, the main power line cross section is equal to or greater than 2.5MM2, and the output line is not less than 1.5MM2. To ensure optimal performance, a well contacted negative (iron) wire is required.good Quality Sound Quality: In order to obtain the best sound quality, the air source of the speaker should be introduced directly from the air reservoir, which needs to be drained regularly to avoid affecting the service life of the solenoid valve.Working Conditions: The working pressure range is 0.3 to 0.9MPa, the ideal range is 0.42 to 0.68MPa, and it can withstand temperatures from -40C to 80C. Material and Long Service Life: This Train Air Speaker is made of copper, which is and has a long service life. Specification: Working v: 12V-24VWorking pressure: 0.8-0.9MPAWorking frequency: 500-800HZPitch: vibration and soundInstallation method: Tracheal joint installation Size Chart: 35cm/13.77" 33cm/13" 28cm/11" 21.5cm/8.5" 1 5cm/5.9" 9.5cm/3.74" Package Includes: 1 set 4 Trumpet Train Air Speaker Note: Please allow slightly errors 1-2cm differences due to manual measurement.