Sellita SW510 Swiss-Made Chronograph Movement: The Sellita SW510 chronograph movement is world renowned for reliability, accuracy and functionality. It is fitted with a 3pm minute sub dial, 6pm date window and 9pm seconds sub dial. Our brass chronograph buttons on the side of the case start / stop the chronograph stopwatch and reset back to 12o'clock. The power reserve is 48 hours with 27 jewels built in Sellita's facility in Switzerland. CASE MEASUREMENTS Diameter 41mm, thickness 16mm, lug to lug 49.5mm, lug width 20mm CASE EXECUTION Brushed case, aluminium rotating bezel, laser engraved caseback ring and open exhibition glass caseback GLASS Flush sapphire crystal finished with a medium blue tint and double sided anti-reflective coating DIAL Matte sandwich dial with cut-out indices, green  Super-LumiNova sub-layer, 3pm minute sub dial, 6pm date window, 9pm seconds sub dial, polished hands and fire bell chime inspired seconds marker. CROWN Stainless steel crown with a brass inset made from a 100 year old British brass firefighter's helmet STRAPS All straps have a 20mm lug distance and a quick release functionality allowing you to change straps without any tools required WATER RESISTANT 100 Metres / 10ATM