Consists of a zinc coated u-bolt base, double socket arm and universal spring loaded X-Grip IV holder for 5" large phones and tablets. Included in this package is hardware that will accommodate rails from 0.50 to 1.25 in diameter. 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. X-Grip IV Holder.