Park FR-8 Freewheel Removal Tool
From Park: Removes four-notch freewheels from "flip-flop" BMX hubs with 30 x 1mm threads. One-inch base to fit end of SR-1, FRW-1, adjustable wrench or bench vise.
From Porkchop: This would be for a freewheel on the "small side" of your flip flop hub.... or, for newer freewheel hubs, which only have a smaller metric threaded side. Not sure what size you have? 13T, 14T or 15T freewheels are going to be threaded onto a 30mm X 1mm hub. 16T or larger are 1.37" in diameter and are going to take a Park FR-6 freewheel tool.