Ok I picked up a basket case ms660 a couple weeks ago and im now getting all the parts to make it a running unit. But the carb I recieved with the rest of the saw is what you see in the pictures. But my air filter base plate has that dime sized oval above the carb for the newer style carbs with that air suction compensator thing. Im not sure what carb I have here or what it goes to. There are three fittings, one black plastic on the side that goes to the fuel tank. the other 2 fittings are aluminum or steel and are on the top and bottom side and i dont know what goes to wht.