ESU 50012 ECoSBoost External Booster (7A)ESU ECoSBoost Reliable Power Expansion for Large Layouts On larger model railways, the power demands of multiple locomotives, lighting functions, and accessories can easily exceed the capacity of a central station. The ESU ECoSBoost is designed to solve this problem by dividing your layout into power districts, each supplied by its own booster. Perfectly matched for use with the ESU ECoS or the Mrklin Central Station, the ECoSBoost ensures smooth,