Hey Craig
The flaps themselves are the same, on the dual port the linkage between the two flaps are different. The SP has only a flat bar with four holes that connects directly to the flaps and it's secured by those spring style clips. The DP(the one you have in the pic) has a bar with two offset bends and two holes, then on each side there is a "T" connector with two connections to the flaps and one to the bar. These use the other type of clips but the spring type can be used too.
One thing about the DP bar; i found two bars exaclty the same but with the hole for the spring in a different place. Make sure the one you have has the correct hole in order to properly tension the spring and open the flaps when needed.
Abel