CONSTRUCTION MASTER PRO-4065: This feet-inch-fraction calculators feature a broad range of nearly automatic construction/math problem solutions. From its single key solutions to arc length, circumference, circle area, board feet conversions, and weight-per-volume conversions, this popular calculator works in most common construction or building dimensional formats. It adds, subtracts, multiplies and divides in feet-inch-fractions, decimal feet (10ths, 100ths), inches, fractions, decimal inches, yards, meters, centimeters, millimeters, and square and cubic dimensions. Plus, it converts to and from any dimensional format. This model features advanced dedicated key functions for blocks, roof areas, and footings. Enhanced stair, rafter, rake wall, and circular cone functions. Models includes easy-to follow pocket reference guides in English and Spanish, English and Spanish How-To CD and user guides, long-life batteries, and a full one-year limited warranty.