Altra Worm Gear Box Series-ALM. Die - cast Aluminum Case, Worm gear units with electric Motor/ mechanical varitor in double Stage Suitable for Power Upto 15.Range: Power range from 0.06 kW up to7.5 kW, Ratio range from 7.5: 1 up to 1600: 1. Sizes: Centre Distance from 30 mm up to 130 mm. Type: Worm - Available in Foot & Flange mounted Versions.