Also referred to as push lock or push on hose fittings, they are a great fitting to use when pressures are not exceeding 300 psi.  When used with the proper Socketless hose, these fittings push into the hose and hold up to 300 psi WITHOUT the need for a clamp.   Available in brass, steel, and aluminum, these are a great fitting to use in hydraulic return, coolant, fuel, and low pressure transfer applications.  Available in ¼” thru 1” and with JIC, SAE, and NPT threads.