The 15mm stainless steel knobs generate higher centrifugal forces while working which enables a tighter serving!
The weight difference between the Standard Spindle (50g) and the Profi Heavy Spindle (80g) is 30g!!...60% more!!
You may equip the spindle also with two different steel Knobs, one with 9mm and one with 15mm to generate an imbalance, to make it easier to spin the Winder. (optional)