Back Cover, Black, (6) Screws, 4-13/32 in L, Honeywell, Mfr#: MCX3-BC1B

Back Enclosure, Product Type Back Enclosure, Series GasAlertMicroClip X3, Sub-Brand BW, Color Black, For Use With GasAlert Microclip X3 Series, Includes Alligator Clip, Screws, Overall Length 4.41 in, Overall Width 2.41 in