XF20/M20/D Straight Cable Conduit Fitting, Nylon 66 Black Black. The Xtraflex type XF range from Adaptaflex is a standard weight flexible conduit with fixed external thread fittings that can be assembled by hand. Made from PVCu spiral with a plasticised PVC black covering this conduit offers very high flexibility. The straight connectors and 90° right angle connectors have an IP65 rating.