3/4 inch Tube Size SDR-9 x FPT Flo-Lock Female Adapter. Flo-Lock pipe couplings and adapters make water service line installations easy and provide a leak-proof joint with less chance of pipe pull-out. NDS pipe coupling allow for a reliable connection for Polyethylene, copper tube, or PVC pipes. Buna N O-ring seal and pressure ring to control pressure as cap is tightened. The stainless steel gripper ring helps eliminate pull-out of pipe during installation.