The RAM Tough-Clamp™ includes a 1" ball which can be used to mount a variety of products utilizing RAM's vast selection of mounting solutions. Attach your GoPro Camera, Smartphone, RAM AQUA BOX® Pro or similar light weight device on almost any flat surfaces and square rails. Clamping Dimensions:1. Flat surfaces and square rails from 0" to 1.75" thick2. Round rails from 0.75" to 1.125" OD