Save both water and energy: 4 pieces switch valves for use with 1/2 inch drip irrigation tubing, helping your adjust water to flow or to turn off, save your energy | Easy to use: top red handle turns to adjust or completely shut off water, easy to operate | Operation: self-piercing design use with 1/2 inch drip tubing or insert into larger drip tubing; Fits most tubing 1/2 inch: approximately. 520 - 550 ID range | Good helper for planting: effective way to control water flow to individual plants, planting containers, garden greenhouse, flower bed, patio or lawn | Quality material: good impact plastic constructed and corrosion resistant materials to assure long life