The SoilSaver is made of 100% recycled durable polyethylene plastic. The bin has two slide-up doors for easy compost removal. The four sides are interchangeable. It's easy to assemble and stir/mix for aerobic decomposition and it has a locking lid. The black color bin absorbs and retains heat, enhancing the composting process. 1/4-inch-thick structural foam and black recycled plastic is built to last and hold the heat inside. The SoilSaver offers an optional base sold separate.