And the newer collars are using a different type (for lack of a better word) of shock that produces a different degree of shock. Something about the wavelength(?) which results in a less intense shock. I might be wrong but I understand it as the difference between the zap you get touching an electric fence powered by a 6v lantern battery and placing your tongue across the anodes of a 9v transistor battery.
At least I think this is a newer development, I've just been hearing of it lately. It could be what Dogtra has been doing for years as they have a much greater degree of adjustment than Tritronics. It might explain why the trainer I know best refers to some dogs as Dogtra dogs and others as TT dogs.
