What makes the Swix Evo Pro Edge Tuner isn't the electrically automatic advantage over manually used stones, and files, but how impossible it would be for even the least skilled tuner to mess up edging skis. The included diamond disc is attached to a spring instead of the ergonomic handle, so you won't change the angle when you accidentally apply a little more or less pressure. The adjustable dial ensures precise angle edging whether you want a 85°, a 90°, or something in between. The disc included with the tuner has a fine course, and you can switch it out for disc with medium or heavy coarseness.