Small animal panel heater and a cool aluminum sheet. The panel heater is the type that is inserted into the gap under the cage. It warms up gently just by plugging it in. Marukan - Power: 100V / 4.5W 16 x 12cm The aluminum sheet is a cool aluminum sheet for hot summers. It is not a power type. 13 x 8cm I used them for about 3 months before, and then stored them. *Heater operation has been confirmed.