I installed my first invisible zipper last night and this little foot worked perfectly!  Note - If you have a sewing machine with multiple needle positions, be sure it is set to Center.  My computerized Brother CS6000i defaults to the left and I'm lucky the needle didn't break...not the foot's fault, but mine.  I installed the zipper using a video instruction from Craftsy and the instructor didn't use an invisible zipper foot but mentioned the foot is handy but not necessary.  I disagree!  I can't sew a straight line to save my life and this little gizmo hugged the zipper teeth without bunching, hanging, or snagging and sewed a perfect seam completely straight down the teeth. Without one, the instructor's regular presser foot hung on the zipper top and initially refused to feed the fabric/zipper tape through the feed dogs.  With this foot that did not happen.  When completed, the zipper was hidden exactly as it should be.  The instructor did have a good hint: make your garment seam allowances 1/2" vs. the standard 5/8".  The zipper tape is 1/2" and the edge of the fabric is a good guide for zipper placement.