Space Machine will custom fabricate double ridge twist sections covering the waveguide sizes WRD180 to WRD200. Degree of twist, length and flange types made to customer specifications. VSWR is less than 1.15:1 over the full waveguide band. SME standard twist direction is clockwise*. To order counterclockwise** twist add a dash and “CCT” after Part Number. Example: 90-DTW650-6.0A0102-CP-CCT * “Clockwise Twist” – when the assembly is held vertically and viewed from above, the twist of the tubing progresses in a clockwise direction from top to bottom. ** “Counterclockwise Twist” – when the assembly is held vertically and viewed from above, the twist of the tubing progresses in a counterclockwise direction from top to bottom.