Singer Slant Shank Throat Plate Clamp #172151 (2 ea), Throat Plate Clamp Pin #172153 (2 ea), Throat Plate Clamp Spring #172154 (2 ea) and one Throat Plate Clamp Position Bracket #172213.  Works on all clamping throat plate Singer machines from models 400 through 600. Used working parts, price includes shipping.