Two-stage worm gears are used whenever a high ratio is required within the smallest space available. Ratios are available from 20:1 up to 1,500:1. Z5-Gears are operating at low noise and are suitable for motors with foot.Two-steps Worm Gears are being used where a high ratio is required for the smallest possible housing space. Ratios are available from 20:1 up to 1,500:1. Z 5-Gears are operating at low noise and are suitable for motors with foot.