A high quality switch with a much longer life than previous models available anywhere. Fits most cars, with 20-50 pounds pressure required, instead of stock units that need 60-120 pounds pressure to come on. Standard 1/8 inch Pipe Thread (9/16-18). ATTENTION: THIS updated version of this trusty switch is D.O.T. compliant which includes silicone fluid compatibility and it is capable of 200 -300% more cycles