These waveguide to coax adapters are popular with Satcom Systems. Our WR90 waveguide to coax adapters mate with UG135/U, UG39/U, and UBR100 Flanges. The WR112 products mate with UG51/U and UBR84 flanges. The WR137 products mate with UDR70, UG1732/U and UG1733/U Flanges. WR159 Products mate with CPR159, UDR58, UG1730/U, and UG1731/U Flanges.