Jak-A-Box tipper

Anyone have one?
Are they any good / easy to use?
Can you still use a normal tipper from the 5th wheel with what ever connectors are required on the tractor chassis for the J-A-B?
Are there any alternatives?
Are there any for sale?

Thanks All.

I know that King contractorsin Perth had one on a unit that usually pulled the low loader.There was a thread on here about them ages ago.