you can safely use a 40VA transformer to replace a 20VA or 30VA unit

It arrives with the necessary self-tapping hex washer-head screws

Is the mounting hardware included with this part

utilizing this genuine ICP part is vital for resolving airflow misalignment and preventing pressure switch faults caused by cracked or leaking non-OEM transitions

York S1-55000-328 Detector Head Els PW 17895 you can safely use aThe York S1 55000 328 is a high sensitivity photoelectric duct detector head engineered for rapid smoke detection within environmental air ducts. This OEM York replacement part serves as the direct successor to the legacy S1 55000 225 ionization head, facilitating a critical transition from ionization to photoelectric smoke sensing technology. By utilizing an infrared LED and photo diode arrangement, the S1 55000 328 excels at detecting slow burning,