The Trailer Life Measure is mounted directly on the wheel. It measures the miles traveled by using a fixed ratio which is determined by tire size/rating, for example, 760 revolutions per mile for a typical ST205/75R15 tire or ST215/75R14. Made for Tire Diameters of 26.6" to 27.6". Rolling Tire Circumferences of 83.6" to 86.7". The low profile, lightweight Trailer Life Meter provides an accurate count of mileage traveled for trailers and towable campers in an impact resistant housing. By keeping an accurate count, maintenance operations can be easily performed at the manufacturer's required intervals. Mileage display is 6 digits. Light weight at 7.4 ounces. Made of impact resistant lexan. Accuracy is +/- 2%.

 PROP 65 WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling. For more information, visit www.P65Warnings.ca.gov