Replacement part numbers: P323664, 5001521A, 5001522A, 6501521A, 650122A, can achieve seamless installation Suitable for household fireplaces and stove ventilation systems, used to monitor and controls air circulation, ensuring indoor environmental Built to withstand regular use in various heating conditions, providing a long-lasting solution for vent management Specially designed for furnaces ventilation to ensuring safe operate, with a highly sensitive switches mechanism Monitors the venting systems to potential overheating and ensuring safe, stable furnaces operate, Manufacturer: Kaeltsyn