https://www.dolphmw.com/products/waveguide-assemblies/ Dolph Microwave supplies quality waveguide assemblies, like waveguide clamps ranging from WR28 to WR187. These durable, light-weight clamps allow for the easy mounting of waveguide to most any assembly, with the use of minimal hardware. Please call us with your specification and discuss your needs for custom waveguide assemblies with one of our sales engineers. Following is the shims as example.