This is a simple bolt-on phone holder. It holds your device at a slight upward or downward angle, depending on how it is installed. The opening is about 1/2in wide. Enjoy! If you like this project and wan't to learn more about making things with 3D printers, laser engravers and other cool maker-tech, check out my new book "The Makerspace Workbench" from Maker Media! Don't forget to follow me on Twitter!