Singer 99 Oscillating hook. Part number for Singer #32520. Could use cleaning but all original Singer parts. Part fits Singer 66-4, 66-5, 66-8, 66-14, 66-15, 66-16, 66-18, 66-24, 66K, 99-1, 99-12, 99-13, 99-24, 99-31 and all 99K machines.