The RAM® Quick-Grip™ XL Phone Mount with Medium Torque™ Base – Medium (RAM-B-408-75-1-PD4U) is a universal phone mounting kit with a base built that securely installs to rails. The spring-loaded RAM® Quick-Grip™ allows users to easily insert and remove their phone with one hand, while the adjustable side supports for a secure fit. The RAM® Torque™ mounting base is compatible with rails 3/4” to 1” in diameter. Sizing inserts are included to provide a tight fit while also protecting the mounting surface. The RAM® Torque™ mounting base also includes nylon-insert lock nuts to prevent loosening in high vibration environments. The RAM® ball and socket system allows for articulation at both ends of the double socket arm creating almost infinite adjustment and perfect viewing angles. The cradle is compatible with handheld devices that will fit the dimensions listed below. It is important to verify the dimensions of your handheld device with a case/sleeve/skin when determining the overall size.