This DC-IN board magsafe for the 13" A1278 and 15" A1286 2009 and later.
You get is the magsafe board apple part number 922-9037 there are also a few other apple part numbers.
The BEST WAY TO TELL WHAT YOU NEED IS TO LOOK FOR THE NUMBER ON THE BOARD. This board is 820-2565-A
IF you do not see that on the bottom of your DC board you need to order a different part.