Description: 【Heavy Duty Reinforcement】: Engineered from high strength metal, this mount backing plate kit provides a sturdy and secure anchor point for your off road ladder roof rack. It's designed to withstand tough conditions and heavy loads, ensuring your gear stays firmly in place on any adventure 【Optimal Load Distribution】: Featuring a 4 inch (approx. 10.1cm) diameter, the backing plate effectively distributes the load and over a wider surface area. This prevents damage to the mounting surface and significantly increases the overall stability and weight bearing capacity of your rack system 【Versatile Application】: Specifically designed for mounting and reinforcing off road ladder type roof racks. The included bushings ensure a snug, vibration resistant fit, making it an ideal solution for securing accessories or strengthening the rack's connection to your vehicle 【Complete Hardware Kit】: Each kit includes 1 heavy duty mount backing plate kit, ensuring you have all the necessary components for a straightforward and secure installation 【Essential Upgrade for Off Road Rigs】: A must have for any serious overlander or off road enthusiast. This backing plate kit is a simple yet crucial upgrade that enhances the safety, reliability, and longevity of your roof rack setup Specification: Material: Metal Color: Black Size Chart: Diameter 10.1cm/3.98inch Package Includes: 1 Mount Backing Plate Kit  Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.