The K3MA-J-A2 AC/DC24V is a digital panel meter from Omron's K3MA series, designed for panel-mount installation to display process values like voltage, current, temperature, or frequency from a 4-20 mA or similar analog signal. It operates on an AC/DC24V supply, making it suitable for control panels where a 24 VDC or 24 VAC auxiliary rail is already present.
For a mature part like this, sourcing is through surplus, broker, or last-time-buy channels.
The AC/DC24V supply rating means the meter accepts either 24 VAC or 24 VDC, which is a common auxiliary voltage in industrial panels — no separate power supply module needed if your panel already runs on 24 V.