This box allows you to plug in a Model 500 GE Telephone with a proprietary Bell System connector.Details on how it was created are available on the Workshop 88 blog: http://blog.workshop88.com/new-well-old-workshop-phone/The 'plugbox' STL file allows you to print the top part of the box. The 'plugbox_cover' STL file allows you to print the bottom cover. The box is designed to allow you to put a square of perfboard inside.If you need to change any of the details, the project is also available via GitHub: https://github.com/rlankenau/model-500-phone-adapter