Description: This knob cutter has a round concave edge, which is used to cut the bonsai tree burl and root burl, and would make a circular concave incision. In the healing process, tree's sap would cover this incision and let it heal quickly and excellently smooth. Features: Made of high quality manganese steel alloy, high intensity, strong tenacity and wearability. Remove branches by leaving a small indented cut that heals with little or no scar. Creates a spherical cut in a hollow concave shape that will heal with the least visible scaring and thus create a more pleasing aesthetic. Ideal for removing small branches, protrusions and knobs by cutting into the wood at a concave angle. Ergonomic handles gives you a comfortable hold and allowing continuous use without fatigue. Specification: Condition: 100% Brand New Material: Manganese steel alloy Color: Black Overall Length: Approx. 210mm / 8.27inch Cutting edge: Approx. 20.6mm / 0.81inch Opening: Approx. 53mm / 2.09inch Maximum Diameter/Cutting: Approx. 10mm / 0.39inch Package Weight: Approx. 216g Package Included: 1 x Knob Cutter Note: 1. Please allow 1-2 cm error due to manual measurement and make sure you do not mind before ordering. 2. Please understand that colors may exist chromatic aberration as the different placement of pictures.