This is a gasket kit consisting of a non-conductive gasket, stainless steel screws, nuts, and washers to connect two waveguide flanges together. The FMWGK1008 is the kit made expressly for WR-112 Square Cover/Choke waveguide flange. The gasket is made of Shore “A” 70 silicone elastomer. The screws, nuts and washers are made of stainless steel. Fairview has waveguide gaskets (both conductive and non-conductive), screws and other accessories that you need for your waveguides. Often people can forget to order items like screws or waveguide supports. Fairview has a full line of waveguide accessories available for same day shipment so that you do not have to wait for weeks to get your system working.