Designed for optimized performance on stainless steel tube|Contoured frame allows for easy alignment while adjusting the cutter to make a cut|X-CEL® Knob allows for easy adjustments and quicker cutting|Six individual bearings in the 15-SI and 35S and 12 in the 65S replace traditional rollers, bearings create a smoother cut, and allow for increased speed around the tube|Specially designed stainless steel cutter wheel in 35S and 65S contains bearings in the hub, to decrease drag around the tube for a smoother cut