Just google "Gru-Bee" and click on the company's website. They market gas motors for bicycles among other things. There is a complete spec sheet on their website. Like I said, I think they are only marketing them via eBay at this time. Just type in "Gru-Bee" in the eBay search engine. That link above is for the Chinese factory that makes them, and is only good if you want to buy 200 at a time.