This report describes the test procedures and results of the product evaluation for the ICRI-4TG (Incident Command Radio Interface for four talk groups). The ICRI-4TG is an audio gateway device manufactured by Communications-Applied Technology. An audio gateway device (also called an audio matrix or a cross-band switch) links disparate radio systems to support communications interoperability between dissimilar wireless systems. Such a device simply passes baseband (audio) signals from the receiver portion of one radio to the transmitter portion of a dissimilar radio system.