Have I heard of them.... nope..
but what do I know anyhow...
Early ones are Trailbreakers, if the wheels are empty , you can float across a river or lake. They came with Chrysler engines and a British 3 spd trans (ones guys like to find for Whizzers)
The later dirtbike one was a 340cc I think, had Kimtab Snowflake mags on it.