Type M V-belts used in various sewing machines. Select the size closest to the one written on your current belt. The reference table below can also be used to select the belt you need by measuring the circumference of the belt on your machine.
| Belt Number | Effective Circumference (cm) | Belt Length (inch) |
| M38 | 96.5 | 38 |
| M40 | 101.6 | 40 |
| M42 | 106.7 | 42 |
| M44 | 111.8 | 44 |
| M46 | 116.8 | 46 |