Poseidon is equipment supplier to the German Kampfschwimmer ( combat diver ) and Naval Commandos.

Poseidon Diver P10031 Professional 500m black

details:
case: stainless steel, crown protector
crystal: mineral, extra strong
bezel: stainless steel, luminous point in the triangel
clockwork: Seiko - Quartz
pointer: 3-way (h/min/sec)
waterresistance: 500 m / 1650 feet
strap: neopren (steel buckle), 20mm
crone: screwed, left at 9 o'clock 
bottom: screwed
dial: black
size: 36mm / high 11mm
warranty: 2 years