I've been looking at several versions of these for more than a year, but they always appeared to be too fragile, cost too much and/or they were charging too darned much for shipping, so I never bought one. Now that I finally have, I thought I'd share what I found
https://www.ebay.com/itm/Segway-x2-o...72.m2749.l2649
This vendor (I have no affiliation) finally brought the price down to $14 with free shipping, so I thought I'd give one of them a try - Still a lot of money for a bit of plastic, but they do the job. I think they are made using a 3D printer. These particular ones are quite durable and I don't think we have to worry about breaking them. If there's any downside, it's that they are intended to be permanently mounted on the adjustment knob and nearly impossible to move one from machine to machine, so if you have more than one, you'll need to buy more than one wrench
We take our lean steers apart when we transport our Segs in our van, so we were both getting really tired of the adjustments slipping because we couldn't tighten the adjustment knobs tight enough by hand - Problem solved!
Don