Lot of 3 Vintage ULTRAGUARD & 1 MASTERGUARD Heat Fire Alarm Heat Detector

Description

Offered is a lot of 4 Vintage Heat Activated Fire Alarms
3 Ultraguard Model OI-50  These are from the mid 1950's
1 Masterguard ModelQR 50  This one is newer, vintage unknown
The springs in all 3 are in working order
Review the photos and message me with questions