Design: Ensures smooth flow, maximum flow, no leaks Material: Made of brass, hard, strong, with self-perification ability which can ensure fluid clean. Long lifespan Install：The barb size is 3/4 inch O.D. which can connect to pex pipe directly and be tightened by clamps. Quick and easy installation Application: For pex tubing in heating and water distribution. Compatible with stainless steel clamp and copper crimp ring systems 3/4 inch pex tee fitting, brass coupling adapts water pipes connect tubing with a crimp ring quick manifold push into hose.( 20 pcs)