[Triangular structure, ]The bottom of the RV block has grooves and deep grooves on the wheel side. They provide optimal holding power and effectively stop the wheel from moving. The RV wheel chocks are made of hard plastic material, which is scratch-, oil-proof, moisture-proof and UV-, so you don't have to worry about using it in harsh environments. [Double Wheel Stopper Set]These 4-pack PE are made, and the wheel stoppers fix two wheels at a time. Suitable for most wheels/tires and multi-purpose trailers. [Good traction and bright colors]The bright colors can help you use it in darker environments. With rope, the structure is simple and easy to carry. [Adaptability]: The leveling blocks are suitable for RVs, campers, trailers, cars, trucks and small aircraft. Wheel chocks can avoid the danger of rolling and make your travel . The characteristics of versatility possible to carry a limited number of tire gears and can be used in a variety of places. [Easy to carry]: Vehicle wedges avoid traditional steel rings that are difficult to grip and easy to rust and bend. Instead, the compact size and sturdy handle more convenient to carry, use and wrap up. [Dual Wheel Stopper Set]These 4-packs are made of PE UV inhibitor (hard plastic), the wheel stoppers hold two wheels at a time. Dimensions (8.3inch L x 4.7inch W x 4.3inch H) fit most wheels/tires and utility trailers. Colour:Yellow Material:PE Package Contents: 4 x Wheel Chocks Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.