These fittings work by securely locking onto the pipe or tubing through a compression mechanism. As you tighten the fitting, a ferrule compresses against the tube, creating a tight seal that prevents leaks while ensuring a strong, durable connection. Our VIS-LOK technology means that every fitting includes a check ring, providing you a guide on how much to tighten the fitting. Simply tighten until the check ring comes off and you’ll know you’ve got the perfect connection.