The SB5 Smart Booster adds expanded and updated features to a Power Cab DCC system. The first and most noticeable feature is additional power (5 Amps) to run trains and accessories. Your PowerCab used with the SB5 can now be unplugged and used in true walk around fashion. It no longer needs to remain connected for the system to work. Up to 6 cabs can be used with the SB5 (Cab address range 2 through 7). Equipped Cabs have up to six recalls each when used with the SB5. Additional 5 Amp boosters (DB5) may be added to the SB5 for even more power handling on larger layouts.