compatible with brother commercial sewing machine models: db2-b755 & db2-b755-3. compatible with singer commercial sewing machine models: 241-11, 251-21, 95-1, 95-2, 95-10, 95-12, 400w21, 400w22, 400w23, 400w24, 400w28, 400w29 & 400w33.