Luminox Leatherback Sea Turtle Giant 0320 Series XS.0337. The Leatherback Sea Turtle collection is being introduced at a lower price point making it accessible to a broader consumer base, but it still has all of the important components that make a Luminox watch lightweight, tough and reliable. Those features include an incredibly strong CARBONOXTM case, 10ATM water resistance, extra hardened mineral crystal and a stainless steel double gasket protected crown. Rather than all twelve numerals, the Leatherback Sea Turtle watches have six Tritium gas tubes marking 2, 4, 6, 8, 10 and 12, while providing the same 24/7 visibility that Luminox consumers depend upon.