The Bio-Stack Composter is a somewhat unique design. It comes as several panels that creates sections that you "stack". This allows the bin to grow as your waste material and your compost bin needs grow, up to several feet in height.
The other use for this is the simple act of turning the pile. With most bins, if you want to turn the pile, you have to either have another bin or location for a pile, or you use a compost turning tool within the bin, which usually does just a fair job of turning the pile.
With the Bio-Stack, you can take the top section off and use it to start another bin location next to the current one. You then turn the pile material into the new location until the next section can be taken off, and it is assembled on the new pile, until you have created a new bin location adjacent to the old one, but you have completely turned the pile, but only have to buy one composter. Of course you do need a little more space than just the space for the composter, but that is minimal.
With it's hinged lid that will keep excessive moisture out of the bin, this is an excellent choice for a first compost bin.