Stührling Original Meridian GMT. This model is a quartz-movement, diver-style watch known for its distinctive black and blue "Batman" style GMT bezel, which allows tracking two time zones simultaneously. 
Key Features
Brand: Stührling Original
Collection: Aquadiver, Meridian series
Movement: Swiss Quartz with GMT (dual time) function
Case Diameter: 42mm
Water Resistance: Up to 10 ATM (100 meters/330 feet), suitable for swimming and snorkeling
Bezel: Bidirectional, coin-edge, black and blue (often nicknamed "Batman" style)
Dial: Black, with luminous hands and hour markers for easy reading in low light
Bracelet: Fully adjustable stainless steel link bracelet.  The watch is in excellent used condition with box and papers