Fits Vans 6 inch dia x 2 inch wide tire.   The chock side panel swings open to allow the chock to be fit in place and secured in about 10 seconds.  Approximately 50 lb load resistance when installed and the chock rotates with the wheel to secure all directions.  Good for an extemely worn tire (as shown) or new.  Uses a 1/4 inch dia quick release pin to secure.   A nut insert is provided to attach the pin to a lanyard if desired.   Made from UV resistant plastic.   Total weight = 6 ounces (170 grams).    This one chock should be sufficient to secure the aircraft in a 40 mph wind.  
 
The development of this chock is described here.