Found an owner · ref 100012
Certina DS-2 "Turtleback"
Certina · DS-2 automatic · ca 1971
About this model
Certina patented the Double Security case in 1958 and put it on sale in 1959. Instead of bolting the movement to the case, DS floats it: an elastic ring takes the shock from the sides and a pocket of air sits under the dial, so a knock travels around the mechanism rather than into it. The crystal is deliberately thick and the caseback reinforced. Certina sold the idea with a stunt, strapping watches to a 27 kg weight and dropping it six metres onto concrete, and the first DS went up Dhaulagiri with the Swiss team that made the first ascent in 1960. The DS-2 is the second generation of the same construction.