some sewing machines come with a shorter needle clamp screw and cannot be used with certain presser feet such as a walking foot, ruffler/pleating foot, free motion darning foot, knit foot, etc. this is because the arm of those feet must go over a needle clamp screw to make it operate properly. guaranteed to fit brother sewing machine models: ls1217, ls1520, ls1717, ls2125, ls2220, ls2720, ls2725, ls2820, ls2825, ls2920, vx1120, vx1125, vx1140, vx1250, vx1435, vx2240 guaranteed to fit kenmore sewing machine models: most models beginning with 158. guaranteed to fit viking sewing machine models: 6000 series
