"Unique enclosed design virtually eliminates warping or torquing. Requires no brackets or adjustable torsion rods, making cleaning fast and easy. 6in base allows Screed King to float in any slump of concrete while the curl edges help roll excess concrete back to the rakers. The MAGFLO boards are constructed of light magnesium that doesn't react with concrete like aluminum screed bars. Ergonomic mounting levers make for quick board removal - no tools required. Designed for a single powerhead. 12ft. wide"