【Brass roller with open retaining ring】Brass roller design, unrestricted forward and backward movement when sharpening knife, consistent direction, non-slip, smooth and safe. The open retaining ring design ensures that the roller does not shift when sharpening the knife and always remains centered. 【Exquisite and Durable】Made of high quality stainless steel material, not easy to rust and durable. 【Fixed angle, easy to use】Turn the nut counterclockwise, clamp the chisel or other tool, and move up and down to adjust the angle. Then tighten the nut clockwise, the blade fits smoothly to the whetstone or sharpener, and slide the knife back and forth until your tool is more precise and sharper! 【Wide use】Suitable for sharpening wood chisels, planes, blades, carving knives, carving knives, planing irons, and flat chisels. It must be a good partner to help you sharpen your knife’s edge! Saves your energy, but works well.