Add a branch to your irrigation system using the Insert Barb Tee X 1/2 in. MPT Adapter. This fitting has two 17mm barbed ends to connect to tubing or dripline, and a 1/2 in. MPT connection point which screws into a 1/2 in. FPT connection point such as the threaded end of pipe. This insert tee fitting is made of acetal treated with UV inhibitors to prevent fading and cracking.