An assembly for connecting an air connection fitting to a pneumatic de-icer of an aircraft includes a molded base and a machined insert. The molded base includes a flexible material and forms a sealing interface with a portion of the pneumatic de-icer. The machined insert is set into the molded base and includes a radially inward threaded surface that forms an opening extending axially through the machined insert. The radially inward threaded surface is configured to mate with a terminal end of the air connection fitting.