Make quick work of removing four-notch freewheels from flip-flop BMX hubs with the Park Tool Freewheel Remover: BMX freewheels with 30x1mm threads. Made from heat-treated alloy tool steel, this remover has a one-inch base to fit your wrench or bench vise, and uses a thin wall construction to get the job done without the removal of cones or locknuts. This particular remover has four notches approximately 25mm across measured inside to inside.