This piece is a small scale HO Scale or 1/87 Scale model. It measures about 4 inches long from the back of the shovel to the front of the blade.  From wheel to wheel it measures about 1.25 inches wide; so this is a very small model that fits on the palm of your hand.
 
The wheels can roll freely. There is articulation on the front and back arms. As you move each articulation the pins (pistons/cylinders) also move accordingly just like on the real thing.
THIS IS NOT A TOY. It is very small and fragile. It is made mainly for display purposes.

The model comes in a beautiful multicolored metal can. The can is a much collectors' item as the model itself. 

The can measures 6.25 inches long, 2.75 inches wide and 3.75 inches high.