Baby Lock Single Fold Bias Binder 40mm.Baby Lock 40mm Single Fold Bias Binder (B0421S05A). The single fold bias binder is a quick and precise solution when you want to bind fabric edges or necklines with a bias tape using the cover stitch or double chain stitch. The upper side of the bias tape is folded double and the lower side remains open here. Inlet 40mm outlet 12mm. For use with woven fabrics. Compatible machines: Desire Desire 3 Evolve Evolution Coverstich Sashiko Ovation Triumph