Instructions: 1. This product is applicable to all models with air supply device 2. The working current of the control relay must be greater than 10A 3. The section of the main power line of the relay is greater than or equal to 2.5 mm. 2. The output line is not less than 1.5 mm. 2. The negative (grounding) line should be in good contact to ensure the use effect of this product 4. The horn air source shall be directly introduced from the air receiver to achieve better sound quality: the air receiver must always discharge water to affect the service life of the solenoid valve 5. Air pressure: 0.1Mpa-0.13Mpa 6. The temperature range is - 40~80 ` C 7. The service life of this product is more than 100000 times Note: The air pipe connector of the solenoid valve should be tightened carefully. The filter screen may be blocked during use. It should be cleaned frequently to avoid affecting the sound qualit Package include: 1 x Air motor( Not include Single Trumpet Air Horn )