It is a repurposed MEC child trailer... reconfigured the internal frame to make a press bar and replaced the stock low psi tyres with Comet Primo racing tyres which makes it roll out much faster.

The tote slips in right between the wheels and frame and is secured laterally in this fashion and the tension off the bar keeps it snug, especially when it is unloaded.

Makes it a 30 second job to remove it and use the trailer as a flat bed.