Mike Kijesky made those for several of us.....I think he got $100.00 per.
They require anchoring (we had some screw holes at the beginning of the GSCB take-off area, and some screws in the Pal Park pool area as well....
There was a commercial version made of plastic that the manufacturer/distributor sent Winfred.....it didn't work anywhere near as well....actually came apart.
They are great for trike gear as well as taildraggers....anyone that has had a plane pull the tail wheel out REALLY appreciates them....