All Helix are designated with a number which represents the maximum outer diameter of the helix. Current Range: Series 150   (150mm dia)Series 280   (280mm dia)Series 350 (350mm dia)Series 450 (450mm dia)Series 600 (600mm dia)We do not envisage that the Multi turn Helix range will grow beyond 600mm, as this is in effect equivalent in performance.To a 1200mm … Continue reading Multi & Single Turn Helix