A set of a heater and a thermostat. Purchased in 2018. Used every winter, so there are some stains and discoloration that cannot be completely removed. How about using it as a supplementary heater? ●SANKO Bird Heater 20W An external cage-mounted heating device. I wiped it down, but there are some stains on the heater surface that I couldn't remove. I don't think it's good to scrub too hard, so I've left it as is. Please understand. No instruction manual. ●Marukan Minimal Thermo Connect to a heating device for temperature control. The sensor detects the surrounding temperature and turns the heater ON/OFF to maintain a constant temperature. Safe for temperature management when you're away from home. No instruction manual.