The key to selecting the correct Trailer Life Meter based on your application is to determine the outside diameter of your tire.
Outside Tire Diameter: 31.7" to 32.25"
Rolling Circumference: 99.6" to 101.3"
Typical Tire Sizes:
ST235/85R16
ST225/70R19.5
Typical Wheel Sizes:
16"
19.5"