CRACKMON 224R Crack Width Comparator Gauge (ACI 224R-01 Compliant) Pocket-sized crack-width gauge for reinforced concrete and masonry Conforms to ACI 224R-01 crack-width limits for reinforced concrete Made from tough, flexible modified polyethylene for demanding field use Includes inch and metric rules for cracks up to 2.5" or 50 mm wide Made in the USA of premium materials with unique serial numbers for engineering traceability