Another cost effective packaging item is our clear plastic cases, which range from the common C-shell and Slimpak to Trimpak. The main difference between them is the style. The C-shell looks like a clam that is a transparent, plastic case. The Slimpak is similar to the C-shell but is a full circle. Finally, our Trimpak is has the same transparent plastic look of the first two, but is square in shape.