5-50m Drip Emitter Garden Irrigation Compensation Regulator SystemThere are different options in this auction, you can switch options via button above Buy Now. Please make sure you have chosen the right option before placing an order. 2 4 8L per hour pressure compensating emitter delivers same uniform flow rate from beginning to end of tubing runs. Slow watering rate allows soil to absorb water more completely in the root zones of plants Self piercing design; use with 1 4" Drip tubing Large water passages and self