I ordered this as a Pfaff item number 94162000 as a Pfaff dealer - and it is in the original box with original directions.
What a ruffler can do is AMAZING! Actually, it would be better described as a 'Pleater' as as it works, it is shoving in fabric, it is more like pleats than gathering. Check out the additional photos for some 'education' about this amazing contraption. If you study them, you'll see that it is the amount that the screw on the front top is screwed in that really adjusts how much is 'shoved' in at each stitch. The stitch length (SL in photos) also affects the result.
Interestingly enough, this foot was invented LONG ago and is often found with Featherweight machines!