Innovative Products of America's (IPA) Tire Comparator Type I and Type II, Nos. 9066 and 9067, are intended to help fleets get the greatest fuel economy and tire life possible to reduce costs. Minute discrepancies in tire pairing can cause the larger tire to support a far greater load. The Tire Comparator Type I, No. 9066, allows users to compare tire diameter on single and dual-mated wheel applications for proper pairing, up to 48". The Tire Comparator Type II, No. 9067, provides an easy method of ensuring mated tires are within tolerance using a sliding tolerance gauge that requires no measuring, guessing or even visual inspection. Made in USA.