CUSTOM DESIGNED FOR RIVIAN R1T & R1S: Anchor securely clamps onto the hook behind the driver or passenger seat to add a 17mm ball mount for accessories. | PREMIUM MATERIALS: Manufactured in the USA from high-temperature PolyHex plastic and stainless steel fasteners for exceptional durability, heat resistance, and overall reliability, ensuring a long-lasting and robust product. | STANDARD 17MM BALL MOUNT WITH CLAMP: Compatible with phones, tablets, and other devices from 5-11". | INNOVATIVE DESIGN: Clamps onto the seat back hook without touching the seat covering and plastic or wood trim. | RELIABLE AND SECURE MOUNTING: Works with 17mm mounts that are compatible with phones, tablets, and many more devices.