Portable Fire Alarm.
This portable alarm is activated by moving the slide switch to the 'On' position. The thermostatic switch then connects the battery to the silicon-controlled rectifier when room temperature reaches
135 degrees F.
You can take it with you in your travels. It's slightly bigger than a pack of cigarettes - 2 x 3 x 4 inches.
One page ( 1 sheet - front only ) B & W photos, illustrations, expanded view, parts list and instructional narrative.
My plans are from original source materials such as books, magazines and other publications and the pages are carefully removed.