Storage for rulers

I need to carry around several 600mm rulers along with other equipment. They got bent in the boot of the car with all the other gear, so I designed some secure storage with a screw on lid for them. Using the bottom, middle, top and lid sections you can store a 600mm ruler. Also included a short middle section so you can mix and match to suit other lengths. Bottom three sections are a tight fit together aided by a little CA glue.