I have at least ten commercial type smoke or heat detctors. The units
are marked "PYR-A-LARM" Cerberus Licensed, made by Pyrotronics, a
division of Baker Ind. Inc. These came from a military auction, so can't
guarantee them, but may make interesting experimental item. They have a
heavy black bakelite base that bolts to a ceiling electrical fixture box
with 8 sets of terminals for wires. The rest is aluminum with a screen
at the bottom and extends about 4" down from the base, 3" dia. Looks
expensive. $5 each plus ship. NOTE: Please REMOVE the "nospm" to reply
or call
334-347-5281.