Push-to-connect tube fittings, also called push fittings, connect tubing without the use of special tools, glue, soldering, or unions. Tubing is pushed into the fitting and held in place by a grab ring which also disconnects the tubing for frequent changes. Push-to-connect fittings are available in a variety of materials for air, non-potable water, DOT, potable water, and refrigerant applications.