Our Plan Measuring Wheel measures plans fast & accurately. The PlanWheel SA2 is the perfect tool for taking scaled measurements from blueprints, plans and maps. Just select the built-in scale factor to match the plan and roll the wheel. The measurement is displayed instantly. The PlanWheel SA2 is a Stand-Alone model. It does not interface with your computer. 111 built-in and thousands of available user-defined scale factors. Includes all common scales – imperial and metric too Calculate auto-scale factor from reduced, enlarged or odd-scale drawings Measures in inches, feet, yards, miles, centimeters, meters and kilometers Calculates square and cubic dimensions for regular areas and volumes Counter and adder buttons on probe tip let you count items or add fixed lengths as you scale Create, store and retrieve 2 user-defined scale factors Clear, audible tone indicates wheel movement Automatic shut-off assures long battery life Low battery indicator Plus / minus (+ -) mode allows user to simply roll backwards to deduct an over-rolled measurement