Bonsai Tools 205 Mm Knob Cutter Round Edge Cutter 3Cr13V Alloy Steel Name: knob cutter SN-RE-205 Brand: Quality: standard Material: alloy steel (3Cr13) Overall length: 205 mm Surface Treatment: sanding Edge Hardness: HRC50 quenching by the high frequency coil. Cutting function: cutting wet branches with a diameter less than 8 mm.