Hamsters are sensitive to cold, so this setup includes a heater. It's a GEX Glass Harmony 600 that has been used for about two years. The top rear has been notched to accommodate a DANTOTSU M heater (see photo 4). It comes with a thermostat for easy temperature adjustment. The DANTOTSU was removed and used during the non-winter months. It can be easily removed with a Phillips head screwdriver. There are some bite marks from housing a Golden Hamster, but it doesn't affect functionality. A running wheel, large and small water bottles, and a temperature/humidity gauge are also included.