Compatibility Assurance: Specifically designed to fit most 4.5" angle grinders, this backing pad features a standard 5/8"-11 threaded spindle. The inclusion of a zinc-alloy locking nut ensures a secure, wobble-free attachment, enhancing safety and efficiency during use. Advanced Material Construction: Engineered with a three-layer design, this backing pad incorporates spiral ribs for optimal airflow, a sturdy polypropylene base for , and an alloy reinforcement ring to withstand high operational speeds, ensuring and durability. Versatile Applications: Ideal for a wide range of grinding and sanding tasks, this backing pad is perfect for metal fabrication, woodworking, and preparation in both residential and commercial construction projects, offering flexibility and reliability. Enhanced Features for Superior Performance: The spiral rib pattern not only promotes better airflow but also minimizes heat build-up during operation. This design, coupled with a reinforced structure, ensures the pad maintains its integrity even at high RPMs, compatible with various resin fiber discs. Tool-Free, Easy Installation: This backing pad is designed for quick, hassle-free setup without the need for additional tools. It features clear alignment markers for accurate positioning and includes an anti-loose locking nut to prevent detachment during operation. Color: Black Material: plastic Package Contents: 2*backing pad 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.