Our billet shifter knobs are designed to fit the curvature of the hand. As you pull down two fingers go underneath the curve and two on top, then when you push it fits the palm of the hand. We added the custom smooth knurling for grip it doesn’t matter if you are barehanded or wearing gloves. They come with 1/2-13 threads to fit the Atlas shifter or anything that has 1/2-13 threads. The threads are cut at the bottom for the perfect fit.