The ARC (Cessna) IN-525B is the standard VOR/LOC/Glideslope Indicator for the 14 volt RT-328 series NAV/COMMs. It uses two pendulum meter movements. The ARC IN-525B's features include:
- Back course annunciator light
- Snap action TO-FROM flag
The ARC IN-525B may be used with the following NAV/COMMs. Neither the IN-525B nor these NAV/COMMs contain a Glideslope Receiver, so it needs that information from another source. The most common solution is to add an ARC Glideslope Receiver, such as the R-443B.
- RT-328A NAV/COMM (360 channel, crystal solid-state)
- RT-328C NAV/COMM (360 channel, synthesized solid-state)
- RT-328D NAV/COMM (720 channel, synthesized solid-state)
- RT-328T NAV/COMM (720 channel, synthesized solid-state, TSO'd)