Hakko FT8003-81 - Hot Knife Conversion Kit The Hakko FT8003-81 is a hot knife handpiece and is compatible for use with the FT-801 and FT-802. The FT8003-81 features a knife blade design, and is ideal for use with ultra thick wires, as well as expando and other wiring braids. This item has an ultra slim, ergonomic handpiece, is ESD safe and provides easy insertion and removal of blades.