Emergency situations require that first responders have adequate communications inside buildings. EMR Corporation provides VHF and UHF bi-directional amplifiers that can be the backbone of an effective distributed antenna system (DAS). The 840622/72 is a 60dB gain VHF repeater with 37dB of composite output power. NFPA Compliant, 1SC-12 Upgrade. Can be used with a single or multiple frequency pairs with 3 MHz separation or multiple pairs with 5 MHz separation. For multiple pairs with 3 MHz separation, maximum UL and DL passband is 500 KHz with 2.5 MHz guard band and 2.5 MHz passband with 2.5 MHz guard band for 5 MHz separation. Specify frequencies when ordering.