Electric Wheelchair Gearmotor Supplier

Does anybody know who manufactures the wheel chair gearmotor you see on most electric wheelchairs?

I can find these things used on eBay or on craigslist usually, but they’re typically a little worn and beat up. I’d like to buy several new pairs but the prices on most third party websites seem a little bit high for my taste.

Just wondering if anybody had some information about where these things are typically sourced or produced.

Happy Thanksgiving!