Sewing Machine Spring Foot Clamp For Quick & Easy Presser Foot Change. Part # : SFC2 This Item replaces the Thumb Screw that holds the Presser Foot. It allows for an instant, quick change of Presser Feet without using a screwdriver...just push the button. This is a permanent item that will not loosen over time. It is commonly used in Sample Rooms and Repair Facilities. Fits most high shank, single-needle home and industrial sewing machines.