Size4 covers / set, fits entire tire diameter up to: 19 ' - 22 '. Its NOT the Rim Size, please refer to our fitting guide picture for size selection. Multi-Function It can be used in all year, protect the wheel and tire from dust, corrosion, dry rot, snow, ultraviolet and high temperature. When the tire cover is dirt, easy to clean and wipe by water. Compatibility Perfectly compatible for Jeep, car & truck, boat trailer, camper, motor home & RV, truck and SUV, or anything with the correct tire size. Unique Design Perfect wind resistance capacity, the elasticized band and auto-lock design keep the tire cover stay on the wheel even on windy days, easy to put on and remove. Durable water resistant coating and bonded with soft, non-scratch backing, It can prolong the service life of tires. Precautions Please pay attention the size is the full tire diameter not the hub diameter. For example, your tire is P205 / 55R16, A = 205 B = 55 C = 16 Diameter = A * B / 500 / 2.54 + C = 205 * 55/500 / 2.54 + 16 = 24.88inch. Replace the number 205 55 16 with your tire data then you will get your real tire diameter.