Professional Measuring Wheel, 12-In.suitable for measuring vertical, horizontal or curved surfaces, the Lufkin large contractors measuring wheel displays surface dimensions in inches and feet for quick and accurate distance calculations. it features a 12 1 2 in. wheel with rubber tire for superb traction on job sites with uneven terrain or long indoor expanses. the analog counter dial calibrated to the wheel rolls over to zero after reaching 10,000 ft.