There are only two other CCL VLS in the world.
One is the Russian UKSK VLS.
And the other is the Mk. 57 VLS used in the Zumwalt.
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Mk57 uses a central exhaust system where each cell's exhaust goes downward into the central system, and is finally ejected via two exhaust tubes. One at the beach end of a 4 cell module of mk57 system. The whole 4 cell module has thus 6 doors. 4 are for the missiles and two slightly smaller ones, one at each end, are for the exhaust.