Raindrip 25PK 1/2 GPH Mini In-Line Dripper. It is a pressure compensating dripper with a flow rate of 0.5 gal/h. It has a 1/4" inlet size and a 1/2" outlet size. It is made of durable plastic and is UV resistant. It is easy to install and can be used in a variety of applications, including drip irrigation, container gardening, and greenhouse irrigation.