Safeguard your nitrous system with NOS pressure safety switches! These switches prevent your nitrous system from engaging when the fuel pressure is below a safe level. These easy-to-install NOS versions for all carburetor and direct port nitrous systems are preset at 4 psi and most are adjustable from 4 to 7 psi (non-adjustable also available). Have an EFI application? NOS offers safety switches preset at 50 psi that are adjustable from 30 to 70 psi. Stay safe with Nitrous Oxide Systems pressure safety switches.