Turn on the air pressure switch if the pressure is below 90 psi, turn off at 120 psi. Lifespan: 100,000 cycles, long life. Please contact the seller if any problem occurs. 1/4-18 NPT male thread: Single connection for air tank, train, air horn, or air pressure switch. DC pressure switch: Compatible with 24V and 12V systems. Also available for AC 110V, 120V, and 240V applications. Multipurpose air pressure switch: Suitable for air horns, trains, air tanks, and other pneumatic systems. 1/4" NPT male thread: Quick connection design for easy installation; no special tools required. 90 PSI ON / 120 PSI OFF: Automatically activates when pressure drops below 90 PSI and deactivates when pressure reaches 120 PSI. Compatible with DC and AC power sources: Includes models for DC 24V, DC 12V, AC 110V, 120V, and 240V. Versatile usage: Ideal for train horns, air tanks, suspension systems, and other air compression applications. Product includes: 1 x 90120 PSI air compressor pressure switch. Note: 1. Due to variations in monitor displays and lighting conditions, the actual product color may differ slightly from the image. 2. Manual measurement may result in slight length discrepancies.