The use of a running wheel is an essential tool whether used to enrich an animals environment or to study the effects of exercise on cancer. The Running Wheel is used with the open field system to generate not only wheel rotation, but measure circadian rhythms while in an enriched environment. The running wheel easily attaches to an acrylic animal cage that fits inside the open field frame. Open Field – Locomotor Activity Both mouse and rat wheels can be used. You can even study two mouse wheels at a time per open field monitor.