Fiber Cap holder

In the coarse of working with fiber optic cables I inevitably need a place to store the small dust caps. If I cant find a small cup I sometimes stick them to a piece of tape and hope I don't loose them. I always thought it would be nice to have a small cup and lid that could stick to the metal rack or piece of equipment I am working with. I designed this cup with the use of 3 rare earth magnets to attach the cup to something metal. Two in the handle and one in the base.
Maybe someone can design a flip lid that is attached.