Here is the UK Distributor:

Sprint Booster - Electronic Throttle Control Replacement for Faster Response and Greater Acceleration

2 models now available - the new one is switchable so it can be set in either standard mode as well as booster mode.

They are manufactured in Greece and there are distributors all over the world. I did have one but sold it on a while ago. We had a craze on them here a couple of years ago. The product is good fun, but this combined with the throttle re set is amazing,

Have fun!