Peruzzo 4 bike, tow bar mounted cycle carrier. Full spec and details and a rather snazzy video found here:
Retails at over £350 plus accessories. Comes with wheel extensions and all the items as shown. Bought a trailer shortly after its purchase so is almost unused!
Around 20kg so quite expensive to courier but happy to do so at cost, for you to organise your own courier or for collection in person.
£175 plus delivery (at cost).