Bobbins class 15 class plastic
For Singer models 1530, 1588, 1590, 1591, 118, 132Q, 177C, 223, 233, 237, 239, 1507, 1525, 1732, 3709, 3722, 3810, 3820, 5102, 5107, 5122, 5127, 5522, 5528, 6510, 6550, 7360, 7380, 9910, 9920 9940, XL100, XL1000, XL3400, XL5000, XL6000 Outside diameter: 20.5mm Height: 11.5mm Axis diamter 6.2mm Fits many top loading bobbin machines including Janome and Kenmore.