The D12 Dual 1x2 optical switch is equivalent to two S12 Single 1x2 fiber optic switches in one switch that change state together and cannot be switched independently. See Switch Overview for detailed information common to all Luminos switching products.
The following diagrams show the optical connections for the 2 states. The numbers identify the fiber endpoints. If looking at it as 2 S12 single 1x2s, fibers 1, 6 and 5 make up one single 1x2 while fibers 4, 2, and 3 make up the other.