Material: Made of high quality plastic and metal, durable, stable and does not rust. In addition, the puncher is polished, can be used for a long time. Tight fit: Punch 4mm holes for a snug fit to eliminate waste loss and maintain proper pressure in your drip system. Size: Suitable for 16/20mm diameter polyethylene pipes, 4mm perforations Easy to use: You can use a hair dryer to slightly soften the position of the pipe where you want to punch. Hold the handle of the drip irrigation tube and squeeze the tube, gently press it until the tube is punched.