The Tire Comparator (Type II) is a consistent caliper for comparing tire diameter on dual-mated tires. It provides an easy method of ensuring mated tires are within tolerance. The sliding tolerance gauge requires no measuring, guessing or visual inspection. Simply hold the tool against the tire and slide it across the treads for a quick pass/fail result. The comparator is made in the U.S. from a lightweight, durable aluminum construction. Special tread wear adapter gauges are also available for any rim size.