Developed with a rugged construction and patent-pending design, the ROBERTS® Falcon™ Power 44 Tailblock is the only tailblock to span a doorway. Engineered with a professional installer in mind, the Falcon Power 44Tailblock easily adjusts length from 20.50" to 44" by adding two extensions, each extension measuring 11.75". Internal magnets pull extensions into position, while quick-release pins lock them in place. Dual-edged for convenience, wheel-side down for walls and baseboards; wheel side up for stretching over quarter round. Soft rubber, non-marring surface helps prevent damage to walls and base boards. Versatile, the ROBERTS Power 44 Tailblock can be used with most brands of carpet stretchers on the market today.