1/4 in. Barbed Coupling Fitting, Fits All Sizes of 1/4 in. Drip Tubing. This barbed coupling fitting quickly connects two pieces of 1/4 in. Drip irrigation tubing or taps into the side of 1/2 in. or larger Drip irrigation tubing. Accepts all sizes of 1/4 in. Drip tubing and provides a durable, leak-tight connection. Unique barb design reduces insertion force. To extend water flow to individual plants - connect 1/4 in. Drip tubing to one end and insert self-piercing barbed end into 1/2 in. diameter or larger Drip tubing. Constructed of highly durable UV and chemical-resistant materials to assure long life.