Allows Water To Be Diverted And Released To Water-Safe Areas Away From Structures, Erosion-Prone Landscapes And Poor Drainage Areas. Opened By The Hydrostatic Pressure Of Water Flowing Through The Drain Pipe, The Emitter Closes As Flow Diminishes Preventing Debris And Rodents From Entering Drain System. 4" Polyolefin Pop-Up Emitter, Center Drive Pop-Up With UV Inhibitor, PVC 90 Degree Elbow With 1/4" Drain Hole. 40GPM.