Tactical Skull Star Spare Tire Cover Dust-Proof Wheel Tire Cover Protector for Jeep SUV RV Trailer Car. Material: Polyester Size: 14 Inch, 15 Inch, 16 Inch, 17 Inch Package: 1 X Spare Tire Cover Cover Size Guide: Tire sizes are listed in the detailed description, please measure before purchasing. Cover Size 14" fits for tire diameter 60-69cm/23-27inch. Cover Size 15" fits for tire diameter 70-75cm/27-29inch. Cover Size 16" fits for tire diameter 76-79cm/29-31inch. Cover Size 17" fits for tire diameter 80-83cm/31-33inch. Spare Tire Cover Diameter Calculation Guide: Step 1: Find your tire parameter. It is written on your tire side. Step 2: Calculate your tire diameter. If your tire is written with P225/65R17, A=225 B=65 C=17. Tire Diameter=A*B/500+C*2.54 =225*65/500+17*2.54 =72.43cm. According to the sizing guide, a 15" spare tire cover is the size that fits your spare tire. Product Performance: The silver-coated sunshade fabric prevents dust, water splashing, sun, and corrosion. It improves the vehicle appearance and keeps the spare tire clean. Applicable Scenario: The universal model is applicable to Jeeps, trailers, SUVs, trucks, and many vehicles. Accessory Structure: Features a nylon rope and buckle for adjustable sizing. Easy to install and disassemble without tools. Washing Instructions: It is recommended to wipe and clean with a wet cloth.