Moonet Tire Cover with Camera Hole, Available for new 2018-2021 Jeep Wrangler JL. SIZE CHART: 32" Fits tire diameter 81cm 255/70R18 - Sahara, Sport Altitude, Sahara Altitude 255/75R17 - Willy's, Moab, Willy's 4xe 275/55R20 - High Altitude, Sahara 4xe, High Altitude 4xe 33" Fits tire diameter 84cm 285/70R17 - Rubicon, Rubicon 4xe How to know the correct size cover for your Tire? You can calculate the correct cover size based on the tire specifications, For example, your tire is written: P255/70 R18, A is 255, B is 70, C is 18, The Calculation Results (CR): (A × B) / 1270 + C, it’s (255 × 70) / 1270 + 18, the result is 32.06". So that 32" size cover fits for your tire.