The ECS is a technical solution to an issue encountered by the mine clearance divers of the Marine Nationale during their many dives: salt crystallizing in the gaps between the bezel and case, thus impeding its rotation. For the 2015 re-issue of the Grands Fonds 300, ZRC has developed and patented a functional solution the ECS was born. A unique system for cleaning the inside of the bezel by circulating fresh water that dilutes and evacuates the sea salt. The ECS is the ultimate tribute to the original Grands Fonds and is perfectly in tune with the brands identity.100% safety is guaranteed thanks to this exclusive strap system using retractable lugs. It is now impossible to place the watch in water without screwing the crown back into its original position. If the crown is not screwed down, the strap cannot be correctly repositioned. This effective method prevents oversights that can lead to technical difficulties.The new Grands Fonds 300 is equipped with an automatic adjustable strap, which allows it to be worn over a diving suit. This unique embedded spring system automatically adapts to the diameter of the wearers wrist for unparalleled comfort. No adjustments are required, as two links on either side of the case extend to accommodate the new diameter.The SELLITA, movement of the ZRC Grands Fonds 300 is composed of 25-ruby wheels, on which Incabloc shock protection was used. Extremely precise, the balance performs 28,800 half-oscillations per hour. With a mechanism diameter of 25.6 mm, it offers a power reserve of 38 hours.