Stainless steel case with a stainless steel bracelet. Fixed stainless steel bezel. Black dial with silver-tone hands and index hour markers. Minute markers around the outer rim. Dial Type: Analog. Luminescent hands and markers. Chronograph - sub-dials displaying: three - 60 second, 30 minute and 12 hour. Hand wind movement. Omega caliber 1863 engine. Scratch resistant sapphire crystal. Pull / push crown. Skeleton case back. Case diameter: 42 mm. Case thickness: 14.3 mm. Round case shape. Band width: 24.1 mm. Band length: 9.5 inches. Hidden folding clasp. Water resistant at 30 meters / 100 feet. Functions: chronograph, tachymeter, date, hour, minute, second, tachymeter. Dress watch style. Watch label: Swiss Made. Item Variations: 311 30 42 30 01 006, 311-30-42-30-01-006, 311/30/42/30/01/006, 31130423001006. Omega Speedmaster Professional Moon Chronograph Black Dial Stainless Steel Mens Watch 3188.8.131.52.01.006.