A trapezoid is a plane figure with 4 sides, only 2 of which are parallel. When closed this box represents a trapezoid at each of its 3 sides. Each compartment pivots off the brass rod running straight down the back corner of the box.

The compartments are able to turn freely around a 360 degree axis and will not tip due to the weighted base (2 pounds of lead shot, 1 pound for the TR-5). The top is a secret compartment which can be accessed from underneath.

The box comes in a variety of woods, commonly birds eye maple, rosewood, and bubinga. The finish is the most time consuming part of making the box and consists of 3 coats of shellac followed by a top coat of paste wax with fine sanding and steel wool between coats. No stains have been used on any of the woods.

The trapezoid is available in 5 or 8 levels with all levels except the secret compartment lined with black velvet.