Arkon's RVRM8825AL RoadVise heavy-duty universal car seat rail or floor mount fits phones with cases weighing up to 2 pounds and measuring up to 4 inches wide, including Apple iPhone 11 Pro Max, iPhone 11 Pro, iPhone 11, iPhone XS Max, iPhone XS, iPhone XR, and iPhone X, Samsung Galaxy Note 10 and Note 9, Galaxy S10, S9, and S8, LG G6, G5, and G4, and Motorola Moto G and Moto X. This mount includes Arkon's RoadVise universal phone holder and an 18” heavy-duty flexible aluminum gooseneck seat rail or floor mount with 25mm (1 inch) double ball-compatible Robust Mount Shaft Arm. Arkon recommends using the RoadVise Holder with skins and ruggedized cases. The low-profile holder keeps rear smartphone cameras unobstructed. The car seat rail or floor phone mount is ideal for those who need easy access to their devices but prefer mounting them somewhere other than the windshield or dash. Loosen the passenger seat track bolt with a socket wrench, insert the included seat track bolt bracket, and then retighten the bolt. Bend the 18” gooseneck and adjust both of the mount's 25mm ball adjustment points for 360 degree rotation of the device. Optional floor brackets are included for installing the mount 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.).