Glensound GS-PASTE201 - Line Powered Telephone Balancing UnitThe GS PASTE 201 is a line powered, heavy duty analogue telephone balancing unit. It allows professional audio equipment such as mixers, talkback systems or headphone circuits to be connected to a traditional analogue telephone line. Features: Provides balanced audio input and output from a normal POTS (Plain Old Telephone System) line No batteries or mains required Input compressor (prevents overloading of telephone line) R C & line balance controls