Heavy material feed dog
To the very best of my knowledge (and I've been full time as a manager / owner in my family sewing machine sales / service business for almost 30 years (with many more part-time before that), I know of no "heavy material" feed dog that has been available for the Pfaff 130. Please keep in mind that the 130, while pretty heavy duty (especially compared to many of today's machines), was never manufactured or intended to be heavy duty in the sense of sewing heavy items such as uphaolstery fabrics (canvas, nagahide, etc.). It was produced with the intent of being a reliable household (non-commercial / industrial) machine with the purpose of sewing light-to-moderate heavy metrails. What exactaly are you trying to sew that leads you to the request of using "heavy material" feed dogs or that you feel Pfaff produced / manufactured such an item?