iM3 Advantage 4:1 Straight Nose Cone. The new Advantage 4:1 Straight Nose Cone is shorter in length and reduces fatigue and wrist strain. Does not require a chuck ring. Fitting a R&R oscillating prophy cup is as simple as pushing it on! The Advantage 4:1 SNC will fit any low speed Motor. Autoclavable with 1 year warranty. Suitable for use with iM3 R&R prophy angles. Reduces the polishing speed. L6250.