They measure 3 inches in diameter without the lid (3.3" with lid) and are made of UV-protected polypropylene and polycarbonate. They come in small, medium, large and extra large sizes, which measure 1.5", 3.0", 4.5" and 6.0" tall, respectively.
They also come with center-divide screw-tops which allow you to connect as many containers together as you like, but each container is separate from the adjoining one as the dividers are not hollow.
They also come with a set of stickers so you can label each container appropriately.
I'm looking forward to loading up these goodies with swag and releasing them into the caching community. I'm primarily interested in seeing how long they last out in the wild after months of being subjected to the elements.
Will the GearPods overtake the ubiquitous film cannister as the cache container of choice someday? Only time will tell.