The Rock Tamers came from
http://www.cabelas.com
and cost me $320 AUD Delivered in approx one week.
Local price at 4x4 camping show (show special) = $430 AUD
RRP at
http://www.rocktamers.com.au/ = $485 AUD (!)
Yes, they are expensive, for sure, but they are nicely built, seem quite heavy duty and the rubber flaps themselves are heavy and huge.
I am pretty happy with them.
They look long in the photos, but I have bigger tyres in the shed, and a lift kit on order with ARB. So that will raise the flaps up a bit off the dirt.
The manufacturer recommends 3 to 4 inches off the ground when your trailer is hitched up.
It's to protect my back window for when towing on dirt roads.
After reading and reading all over the net about different options from Conveyor belt rubber, to VB cartons taped to the back window, I think this will be the best and survive long enough to be moved from vehicle to vehicle.
The quickest way to remove them is to just pull the whole hitch assembly out.