A counterweight is a weight counter balance installed on construction machinery. It is comprised of composite materials, including iron ore. Traditionally, counterweights have not been subject to recycling as the decomposition and degradation process was difficult. However, recycling was made possible by crushing the counterweight, and separating and recycling its respective contents. The Japan Construction Equipment Manufacturers Association (CEMA) was the main player in the construction machinery industry to undertake the development of this recycling system, which was completed in 2006.