A tool to aid fingers in tightening bike spokes nipples.
Most likely you will still use a metal tool for the last turn or two.
My e-bike spokes seem to be non-standard - slightly too big for the size-0 hole in my bike multi-tool thing.
My thing has approximately a 3.6mm square hole (3.7mm in the artwork).
It fits over my 2.3mm gauge 13 spokes. Most spokes are 2mm so you could scale this part up or down quite a bit to suit other nipple sizes.
My tool did one wheel and still looks usable but don't expect it to last forever.