It's a little wire rack sort of like your oven racks, except a lot smaller and with smaller holes. They're used a lot on baking to stop whatever you're cooking from continuing to cook after you take it out of the oven since the metal stays hot for a while. Check at the dollar store like bigfish said, or WalMart or somewhere in the cooking section probably near the cutting boards. They're just little wire rectangles with half inch holes made by crossing wires with 4 bends on the edges to give it "feet" to stand off the board a little bit. If you want it touching the board to drain more or something you can turn it upside down with the feet up and put paper towels under it.

