4 Way compact amplifiers with digi bypass, ideal for use with Sky satellite receivers. Provides power to all remote IR receivers 9V 15mA per outlet max. Powered either from a digital satellite receiver's RF2 9VDC output supply or a separate 12VDC power supply. Short circuit protection - if a short circuit occurs on 1 port it will not shut down the whole amplifier and will continue to operate the other ports.