 The vehicles were extensively modified to add an 8.5KW alternator driven by the engine (keeping weight down, thereby avoiding significant safety hazards), a 52' pop-up pneumatic mast capable of rotating while holding a large yagi antenna, a KU VSAT satellite antenna system, and sixteen HF, VHF, and UHF antennas feeding its radios and interoperable voice and data systems.The Chevrolet Suburban model was the basis of three vehicles delivered in October 2007; this version does not have the pneumatic mast.ECRVs were typically garaged in secure locations around the United States, and deployed when disasters required communications support.