Construction Scale Measure Planwheel SA2 includes 111 built-in scales, The operator can also enter a custom scale in a couple of different ways. The user can either enter the scale directly into the unit or they can use the "Auto-Scale" method by rolling the wheel along a "known" distance from a plan, for example, a plan that has been reduced or enlarged and is no longer accurate in terms of the scale provided on the print. One year manufacturers warranty. Shipping Weight: .400 lbs., Shipping Dimensions: 9.3 X 5 X 1 inches