The Kobalt SpeedFit 4-Piece File Set is part of Kobalt’s SpeedFit system, with a handle that connects to the three files included in the set, as well as other tools in the line. The SpeedFit Handle included in the set is double-ended, with a 1/4-inch connector on one end and a 5/16” connector on the other end. The three eight-inch files included in the set attach to the handle via the 5/16-inch hex shank connection. These files are a mill, half-round and round file. The 4-Piece File Set retails for $19.97.