The Self Piercing Emitters with a sharp barb makes it easy to install, no tools required. Optional insertion tool is available #747542. These emitters have a 1.74 psi internal check valve that helps prevent low emitter drainage holding back up to a 3.9 ft column of water. Prevents contaminants from being drawn into the emitter. The Self Piercing Emitters are pressure compensating and deliver the same flow from 10.15 t 58 psi. Exclusive TurboNet� flow path design regulates flow and provides continuous self-cleaning action during operation.