The Camco FasTen RV Leveling Blocks allow you to stack the interlocking blocks to the desired height for safe and easy leveling. Each block adds a full inch to stack height. Camco’s FasTen Leveling Blocks can be used with single wheels, double wheels, hydraulic jacks, tongue jacks, stabilizer jacks, 5th wheel jacks and tandem axles. The convenient carrying handle easily pulls up for carrying, or twists down to secure blocks together for storage. They are made of UV stabilized resin for years for rugged use and their bright yellow color is highly visible for easy leveling. Compatible with Camco Leveling Blocks. Product dimensions: 17” x 8.5” x 1”. Stack height should not exceed 4-1/2 inches.