The Universal Phone Clamp is the solution for anyone who wants to keep using their favorite case, but don't want to let the convenience of having to attach and remove your bike or motorcycle with one touch. Compatible with all smartphones from 2.3 to 3.3 inches (58 to 85 mm). The clamp width is a screw adjustment system that locks at the width when the dial is pushed. The inside of the clamp part is rubber attached to prevent scratches on your smartphone, and it also prevents it from sliding up and down. Please purchase a separate mount to attach it to a bicycle, car, or motorcycle.