Malco FDC3 Multi-purpose flex duct tool Finely honed double edged knife blade cleanly pierces through the outer skin, instulation and liner construction of flexible round duct and cuts in either direction. Thumb operated latch opens the tool's compound leverage handles and the jaws of a built-in wire cutter to easily sever the exposed wire rib coil of the duct liner Tie-tensioning mechanism to install a nylon tie strap and secure the flex duct take-off collar, use the wire cutter to trim the excess Trimming and installing flexible round duct is now as easy as one-two-three with Malco's FDC3 multi-purpose tool. Trim flex duct and tighten nylon ties with one tool.