This is an All metal high quality Slide plate for Singer Sewing Machine models: 66,66-6,99,99k,99-13,185,185cl,192,285 Spartan. Plate has 2 grooves on the bottom . Your machine should have a pressure spring that slides into the bottom grooves of the plate. When sliding the plate in, you need to push the plate back away from the machine, so the spring falls into the machine.