The SM48825MM car or truck seat rail or floor phone holder mount can be used with all smartphones, including Apple iPhone 12 Pro Max, iPhone 12 Pro, iPhone 12, iPhone 12 mini, iPhone 11 Pro Max, iPhone 11 Pro, iPhone 11, iPhone XS Max, iPhone XS, iPhone XR, and iPhone X, Samsung Galaxy Note 20, Note 10, and Note 9, Galaxy S21, S20, and S10, and LG G7, G6, and G5. The universal design of the Mega Grip phone holder accommodates any smartphone having up to 3.5 inches in width with no height restrictions, making it compatible even when used with a large protective case or skin. This mount includes Arkon's Mega Grip one-touch push-button phone holder and 18-inch flexible aluminum gooseneck floor mount with 25mm (1 inch) ball-compatible Robust Mount Shaft. The phone holder's unique side-grip technology provides a strong grip that's easy to use. Just set your phone in the holder and close the arms to lock in place. A push of the phone holder's side button releases the phone. The car seat or floor mount is ideal for those who want a phone holder for the car or truck but prefer mounting it somewhere other than the windshield or dash. Install the mount to the car's seat rail with a socket wrench by loosening the passenger seat track bolt, inserting the seat track bolt bracket, and retightening the seat track bolt. Bend the 18-inch gooseneck and adjust both of the mount's 25mm ball adjustment points for 360-degree rotation of the phone. Optional floor brackets are included for screwing the car dock directly into the floor of the vehicle. (Warning: Drilling into the vehicle's floor may damage the vehicle. Use caution and consult a mobile install professional to avoid drilling into any sensitive vehicle components.)