Casio watch initiated bomb triggers.
Those are three photos of one device.
The Casio F-91W is said to be popular in Afghanistan and elsewhere.
Way back when I taught riot control in my battalion. Included in the course was bomb detection and what to do if a suspect bomb was found. I made a “bomb” to use as a training aid. It was a box with a clock, battery, old VW horn, two mercury switches and two pressure release switches. No electronics, no computer parts. If the horn sounded it meant the “bomb” went off.
Very simple construction.