Camco FasTen 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. 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. Each block measures 8.5" x 8.5" x 1". Stack height should not exceed 4.5".• 10 interlocking blocks stack to the desired height for customizable leveling• Carrying handle easily twists to secure blocks together for storage• Made of strong, durable molded plastic that won't rot• Safe and easy to use Carrying handle pulls up for carrying or twists down for securing blocks for storage Made of strong, durable molded plastic that won't rot Each block measures 8.5"" x 8.5"" x 1"" | Camco FasTen Leveling Blocks, 10-Pack