This is a great little device! Looks almost new! It lets you use your linear amplifier for high power QSK CW, for Packet, AMTOR and any mode requiring extremely fast switching between transmit and receive. Retails at $400. Selling this one that was hardly used for $300. I will trade toward other equipment such as 300 watt mirage 2m amplifier or other equipment... whatcha got?. Thanks!