Abstract: An assembly for connecting a tubular conduit to an apertured wall of a non-metallic enclosure including a tubular insert seated in the aperture and a threaded, rotatable, hollow hub member arranged to be received by an externally projecting portion of the tubular insert. The closed end of the hub member adjacent the enclosure rests against a compressible resilient ring for sealing engagement and being further adopted for rotatable engagement with respect to the enclosure by means of an interposed washer made of a material having relatively low coefficient of friction with respect to the hub member. The components of the assembly are held together by means of a laterally extending lip formed at the distal end of the insert after assembly of the cooperating elements to the enclosure.