Big, bright and burly, the Ratio 2nd Generation Free Diver Helium-Safe Quartz is a direct contender to all the BIG divers out there, who offer their marvels at prices that shock The Ratio 2nd Generation Free Diver Helium-Safe Quartz is solidly built in stainless steel its crown guarded from all directions by two solid blocks of steel and its unidirectional bezel can handle any impact head-on