With on/off switch Sharpening stages: Smooth blades: 2 stages (grinding, fine honing) / serrated blades: 1 stage Frequency 50/60 Hz Bartscher's MS310 knife sharpener is designed for smooth blades, curved blades and serrated blades. The sharpener is made of diamond (micrometer-sized, monocrystalline) and ceramic stone. It can be operated electronically as well as manually. In addition, it has a magnetic collection plate for grinding particles and non-slip feet.