The RTS PS-20 is a complete independent TW (Two-Wire) power supply. The PS-20 features 2- and 4-channel operation, RTS monitoring, 2-channel program input, audio linking, and 3-mode operation: RTS 2-channel, RTS 4-channel and Clear-Com mode. It also has double the power output of the PS-31 per channel, this increases the number of user stations and beltpacks which can be connected substantially. The PS-20 features two (2) channels of communication where both channels are wet, meaning there is power on each channel (RTS 2-channel mode). In RTS 4-channel mode, the audio signals and DC exist on the same wire. The PS-20 can also be switched into Clear-Com mode. The PS-20 has a 3-pin XLR (male) connector on the front of the system, where a RTS user station can connect and monitor activity on either or both channels. A single PS-20 power supply has 1.8 ampere per channel which means the user can power up more stations (see specifications for details). If additional user stations or beltpacks are needed, two (2) PS-20's can be joined together to double the power capability. A pair of standard stereo plug connectors are available on the back of the power supply to connect two PS-20's through audio linking as well. The PGM IN (3-pin XLR female Program Input) connector can be used to send audio to both CH 1 and/or CH 2.