This pressure switch is designed for high pressure on-board air systems. Ideal for air horns requiring high air pressure. Preset to turn the compressor on when tank pressure is below 120 psi and turn the compressor off when air tank pressure reaches 150 psi Suitable for air horns, train horns, air compressors air suspension, etc. Note: The data is all manual measurement, please allow 1 - 3cm error, due to the difference in light and display, there will be a certain color difference, depending on the physical object received Delivery Quantity: (according to the main image) Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!