It's nothing too fancy, it just holds a standard roll of 100 US stamps. The lid screws into the base container which has a side slot to allow access to the stamps.
The internal screw mechanism was designed to work with all of the polished and unpolished strong and flexible plastic colored materials. You may need to screw and unscrew the lid into the base a few times, slightly increasing the penetration distance each time, to remove loose powder in the screw threads. Once you do this the lid will screw on easily with a nice snug fit.