150 kilo and upwards...
Super-heavyweight is the high-end class. These are the big lumbering beasts that you don't want to drop on your toes! In the UK the weightclass was adopted mostly to allow some overweight (very overweight) heavys. In the US it has been more popular and there have been some really original monsters.
For most people these are not practical due to the huge size and weight, but as a spectacle, they have to be seen to be believed!