Side Cutter (Cut and Hem) Foot
If you want to turn your sewing machine into a serger, this attachment will allow you to cut the seam edge and stitch in one step. Use Straight Stitch, Blind Hem, or Stretch Hemming Stitch (sewing left primary to right cut of seam). You must feed the fabric up and over the cutting edge part, and guide the sewing part of the fabric under the foot. Much like using an rolled hem, or binding foot.
Great Video shows how this works
Cuts Excess Fabric While You Sew and Overlock the Seam In One Pass
you can quickly and professionally finish seam edges without the need for a serger.
*ONE-STEP FINISHING: The built-in blade trims away your excess seam allowance while you sew a zigzag or overcasting stitch around the edge of your fabric, all at the same time
*Important to place fabric carefully over the first platform to allow the blade to cut easily before sewing.
* Not for straight stitch machines
no returns on this foot
Janome, Brother, Babylock, Toyota,various low shank machines