The BLU-4408 is designed to wirelessly operate models with higher stall currents such as some S, O, and large scale locomotives; this decoder features easy-to-use terminal blocks for no-fault wiring and a higher audio amplifier for awesome volume, indoors or out. Blunami decoders can be operated in three different ways: DC, DCC and Wireless mode. Using the Blunami app (iOS versions 8 or later), you can operate your locomotive with incredible ease of use. You will feel like you are in the cab with the amazing new features that Tsunami2 has to offer including: Reactive Dynamic Digital Exhaust, Functioning locomotive and train brakes, injectors, power reverse, and firebox flicker. We also offer a large selection of selectable sound effects including: exhaust chuffs(10), prime movers (up to 12), bells (12), Whistles (90), airhorns (40+), couplers, dynamos and more!