It's not really a FMQing foot, but does curves like was stated above. Don't put money into it for FMQing only. A true darning foot or BSR foot won't limit you to just curves!

If you;re wanting curves to the extreme ... as in circles ... Bernina has a foot that lets you do perfect circle when quilting. I haven't used it, but am totally intrigued about it.

Bernina .... the Queen (or King?) of specialty feet!

I used this foot in a Bernina class (a loaner for the class) and it was very cool going around curves. BUT they referred to it as the "leather roller foot", not as a FMQ foot.

AND, why would I use it instead of my BSR foot (stitch regulator) for FMQ. The BSR is wonderful for FMQ and my stitches are all the same legnth. I can concentrate on moving my piece and it (the BSR) speeds up or slows when I do.