SiS Ergo was a company based in New Hampshire that produced height-adjustable desks. They recently were acquired by Innovative Office Products (IOP) and it seems that SiS was merged with the daughter company of IOP, Hat Collective (https://www.hatcollective.com/products/).
I have a pretty old SiS Ergo Basix Table with an internal chain and manual crank that raises and lowers the table. While trying to fix the table up, one of the gears that interfaces the drive chain with the table leg rotary shaft and links the two legs together sheared apart. The geometry of this gear was pretty complex, consisting of an internal hex and beveled teeth, all at a pretty small scale. I tried finding replacement parts but SiS Ergo said that it was a specified part from a vendor somewhere and they did not have any models or part numbers, so I decided to model the gear out and try 3D printing a replacement. I will also try to get a few CNCed if the 3D looks like a close replacement.
Please find resources on the table sent by SiS Ergo as well as the modeled part in the linked repository.