http://oceanictime.blogspot.com/2018/05 ... steel.html
KAVENTSMANN Deepsea-Stick STEEL
Pressure-tested by the Fraunhofer research institute in Germany to 1200 bar or 12000 meters, the 15mm in diameter by 88mm (screwed)
or 119mm long pen is crafted from German 316 Stainless Steel, and is just what you need to go with your 12000M dive watch when scribbling doodles at the bottom of a deep sea trench.