Scotty’s 139 phone holder offers a phone holder that is legitimately marine-grade. Varying temperatures, constant UV exposure, and saltwater is no match for the engineering-grade materials that Scotty is famous for. Strength, durability, and longevity. Their phone holder is made to withstand heavy use in harsh environments. Positioning and securing your device has never been more effortless and reliable with an easy grip knob that allows for width adjustments securing devices between 2.75 in. and 3.75 in. wide. Another feature is the opening below for access for charging your device while in use.