Sinclair Q2220-E VHF, Band Pass-Band Reject Duplexer is a device that is an essential part in the communication equipment. It ensures that the communication signals of different frequencies do not interfere with each other. The device has a frequency range between 138-174 MHz and can handle power up to 350W. It is compatible with Universal brands and is suitable for VHF bands. The device has a band pass-band reject filter that allows signals between 138-174 MHz frequency to pass through and other frequencies get rejected. The device is designed by Sinclair and is an important aspect of the communication system.