Our Circular to Rectangular Transitions are precision electro-formed components which will enable you to connect standard rectangular waveguide to circular waveguide with a minimum of loss and reflections. Each transition contains a short section of standard rectangular waveguide which gradually transitions to a circular shape. Circular to Rectangular Transitions are available in sizes WR3 to WR42 with circular sizes ranging from 0.0455 inch to 0.4547 inch.