PVC Insert Fitting Adapter - Barb x Spig/Slip 

Buy at:
www.flexiblepvc.net/PVC_Insert_Fitting_Adapter_BARB_x_SPIG_SLIP_p/pi-fitadapt-bxsp-sl.htm
Insert fittings are used in fluid plumbing applications such as irrigation, sprinkler systems, pools and ponds and water service pipe. This fitting is used to adapt tubing requiring a barbed connection on one end to either a slip connection or a spigot connection on the other. For cold water use only.