Bernina foot # 12 Bulky Overlock foot

Although it's called "Bulky Overlock" I don't how to use it to "overlock".  I bought it because I want to use it for piping. It came really handy when I was sewing the Simplicity 2848 dress.

There are two horizontal piping on the front and the back. I made the piping firstly with the narrow zipper foot. Then I pin it between the yoke and the main fabric.

Slide it under foot # 12, and start sewing. The bulky part with the piping should sit under the groove and the needle position should be align to the marking on the foot.

The seam is impeccable.