SCALANCE X accessory; Media module MM992-2LD; 2x 1000 Mbit/s SC-ports, optical; single-mode optical up to max. 10 km. Semi-modular and fully modular Layer 2 switches can be flexibly fitted with 2-port media modules. Using media modules enables: � Extending the network by plugging additional media modules into unused media module slots at the switch at a later time � Changing cabling technology, e.g. conversion from copper to fiber-optic cables or from multi-mode to single-mode FOC, � Bridging longer cable lengths or using existing 2-wire cables (variable distance).Unlimited flexibility during network expansions (e.g. more terminal devices) or conversion (e.g. switching from copper to fiber-optic cables) through modular construction using media modules. Reduction of storage and maintenance costs by focusing on only a few basic unit variants.