The US Department Of Defense Covers the 90 E And H Bend In Rectangular Waveguides by explaining the effect on the field within the guide. Twists, Flexible Waveguide, and the effects of improper bends are discussed. The choke joint and rotating joint are explained both physically and electrically. The actions of the feedhorn and dummy load are explained by mockup And cellomatic visuals. Actual Bends, Twists, Choke Joints, Flexible waveguide, feedhorn and dummy load Are shown.