This is two Very Small Space Exploration Plant Crawlers.  They are made of plastic and are highly detailed, note the wheels.  They are about 1 3/4 inches Tall and 5/8 inches Wide and the coin in the photos is a dime so you can see how small this is.  I bought this as part of a job lot and it is in good condition. 

I will gladly combine these small items to save on the shipping.  Each additional Micro Machine item would be just $.25 for shipping.