https://www.mrosupply.com/speed-reducers/96712600_30277836_boston-gear/
Boston Gear 30277836 HF732-40KEZT-B7-H3-P31 40:1 Worm Gear Speed Reducer 3.2" Center Distance 140TC...
Boston Gear 30277836 HF732-40KEZT-B7-H3-P31 700 Series worm gear speed reducer, 40:1 ratio, 3.2" center distance, 140TC quill flange input, 1-15/16" hollow...