Features 1Enhanced Safety: Trailer jack block is proven by multiple on site tests to keep jacks firmly in place. The blocks can provide stable support in different weather conditions, ensuring your trailer's safety. 2Multipurpose Functionality: Jack blocks feature slots that can fit round jack feet, jack wheels, and square jack pads. This multipurpose feature allows the blocks to adapt to different types of trailers and jacks. 3Heavy Duty Construction: Made of high grade rubber material for long lasting durability, sturdy and durable, the jack blocks are built to withstand the rigors of outdoor use. 418000 lbs Weight Capacity: Provides stable support for heavy load trailers, keep your RV securely in place, eliminating unwanted movement and sway. 5Convenient Design: The RV stabilizer blocks feature 2 holes in its design, making it convenient to pick up and move around. This user friendly design provides ease of operation. Specification Item Type:TrailerJackBlocksMaterial: RubberColor: BlackWeight Capacity: 18,000 lbs Package List 1 x Trailer Jack Stabilizer Block