Vintage Singer sewing machine presser bar tension / pressure regulating thumb screw knob. Compatible with the class 201 and 15 including the 15-86, 15-87, 15-88, 15-90, 15-91, 15-125, 201-2, 201-3, 201K. Very good vintage condition, clean and rust free - Comes with a new felt oil wick. Original, genuine Simanco part #51228