I think it is a bringsmart 5840-3650 , possibly with an 8mm shaft and
   70kgcm torque [1]https://www.amazon.com/gp/aw/d/B07F8Y36PD
   i'm thinking 70kgcm still implies i'll need a gear or pulley to make it
   effective, although I could tie a rope to my ankle and see if it would
   drag me. it would need a spool to collect the rope on.
   turns out 70kg is 154 lbs, which is about my weight, so if the spool
   were under a centimeter radius then it could lift me off the ground
   directly if tied to the head.
   I guess that's the plan!

References

   1. https://www.amazon.com/gp/aw/d/B07F8Y36PD