The Ratio FreeDiver 1000M Blue Dial Stainless Steel Quartz 1050HA93-12V-BLU is for them who love to explore! The Ratio FreeDiver Helium Safe 1000M Blue Dial Stainless Steel Quartz 1050HA93-12V-BLU is a heavy watch. The heavy-gauge surgical steel construction (case, screw-down crown, engraved case-back w/image of a free diver and the deployment clasp) gives it the weight. It pleasantly assures its presence with its heft while increasing the momentum of your hand’s movements, rather than tying you down with its weight. The serrated bezel, the grooved crown and the knurled helium-valve cover – All facilitate a firm grip with wet fingers, with or without the diving gloves on. It is advised not to operate the crowns under wet conditions. Note: You’ll need the helium valve in your watch for times when you are in a chamber filled with breathing mixture; not necessarily diving bells. You open the valve to let the trapped helium out, which got past the gaskets and seals due to their very fine dimensions. A decreasing external/environmental pressure would make the helium to expand fast and damage the seals, crystal and gaskets in an attempt to escape. The helium valve provides an outlet for the built up pressure to escape. Specs and their implications Water Resistance Water resistant up to 3300ft (1000m).Suitable for professional and everyday use.Suitable for Skin Diving, Scuba Diving, Deep diving, Swimming, Snorkeling, Surfing; spear-fishing; moderate to high-intensity land sports. Powerful Luminescence Ratio uses non-radioactive luminescent paint for the luminescence in the Freediver 1000m watch. It is a non-radioactive, radiant paint that's applied generously on the hands and the indices of the Freediver. The paint exhibits greater intensity and longer-lasting luminescence. Japanese Automatic Movement Japanese Quartz MovementCaliber: VX43EJewels: 24Shock protection System: Diashock Dial Analog, blue dial with large, prominent hands and hour indices, covered from the top with a sapphire crystal