Here is a DBX 286S single rack space microphone preamp processor with it's power cable in excellent condition.

Google AI says:

The dbx 286s is a hardware channel strip. It houses a studio-grade microphone preamplifier and four audio processors (compressor, de-esser, enhancer, and expander/gate). It delivers broadcast-quality sound for podcasters, voice artists, and musicians.

Microphone Preamp

• Connector Type: XLR, floating balanced (Pin 2 Hot)
• Gain Range: 0 dB to +60 dB
• Phantom Power: Switchable +48 VDC
• High-Pass Filter: 80 Hz, 12 dB/octave
• Equivalent Input Noise (EIN): -125 dBu (22 Hz–22 kHz, 150 Ω source) [1]

Compressor

• Threshold Characteristic: dbx OverEasy®
• Threshold Range: -40 dBu to +20 dBu
• Ratio: >4:1 (for input levels beyond 20 dB above threshold)
• Attack Time: Program-dependent (>1 second for small increases, down to 10 ms for large increases)
• Release Time: Program-dependent (adjustable ~1 dB/sec to 75 dB/sec)
• Max Compression: 30 dB

Additional Processing

• De-Esser: Features wideband gain reduction with a frequency range of 800 Hz to 10 kHz.
• Enhancer: Utilizes program-controlled shelving for high frequencies (~15 dB max boost) and a specific LF detail curve (80 Hz boost/250 Hz cut).
• Expander/Gate: Offers an adjustable 1.5:1 to 10:1 ratio with up to 50 dB depth.

I/O & General Specifications

• Connectivity: Features 1/4" TRS line inputs and a 1/4" TRS insert, alongside balanced XLR outputs.
• Performance: Delivers a 20 Hz–20 kHz (±0.5 dB) frequency response with less than 0.08% THD.
• Physical: The 1U rack-mountable unit measures 1.75" × 5.75" × 19" and weighs 4.5 lbs, with a 15-watt power draw