BrakeQuip's Tube Straightener, No. BQ1028, has specially designed rollers that reduce the risk of Ovality in the tube. The rollers come made of a hard plastic material which does not mark the tube which is important when working with stainless steel. It either mounts into a vice or bracket mounted and straightens coiled tubing from 3/16" to 1/2" metal tube (even stainless). The unit is fully adjustable and gives a professional result.