as i said on the fire alarm enthusiasts group regarding these alarms, the alarm to the left is the 792 series which was just before the actual integrity series came out. it came in a horn and chime. i don’t ever recall a speaker strobe version of the device coming out. the one to the right is the precursor to the 792 series, the 892. it came in various forms. a strobe plate, remote strobe, horn strobe, and probably a speaker strobe. the strobe plate was made to mount the edwards adaptahorns. now if i may recall, some of the edwards 892 series electronic horns look like actual speakers. ask the others.