Change from twist throttle to thumb?

I just bought my son a blaster and it came with a twist throttle. Where's the best place to buy a thumb throttle and which parts do I need?

Thanks

Man if you love your son you would get that thing off the bike and add a thumb throtle you can go to a local shops and order one from parts unlimited.

It's absolutely aweful. The worst thing I've ever seen. Do I need a different cap for the carb? or do I just need the thumb thumb throttle and cable? Looks like it has a different cap on the carb now.

you can use that cable It will fit it fine. I have a stock thumb if u pay for shipping.pm me if interested

the twist throttle cable did not work with the thumb throttle.

thanks for the offer.