The MTs have an oversized original (non-SE) Zaps' controller. The schematics are almost identical, except for the higher-rated components to support 4 AAA batteries (verses two in the original controller).
Matter 'o' fact, after charging your regular Zap on it's own supplied controller, you can drive it using the MT controller of the same frequency -
I personally like the feel of the MT controllers, as they feel a lot more comfortable and smoother to operate for my big 'ole fingers LOL! -