Hy Capt D, as Grigg has said you have a Motor wheel there, that one appears to be a two piece design. When you go to remove your other wheels, have a good look at them to see if they look the same as the one in your picture. If any of your other wheels have a boxlike structure on the inside of the wheel running around the inside circumference, then don't mess with them until the valve core is removed and all the air is exhausted from the tire, those wheel are dangerous when they have any air in them.
