This is a vintage Realistic Five Band Stereo Frequency Equalizer model 31-1988 in good condition both cosmetically and electronically.
The Realistic Stereo Frequency Equalizer
Output Level: 1V
Gain: ± 0dB
Frequency response: 5Hz to 100kHz
Signal to Noise Ratio: 90dB
Total harmonic distortion: 0.02%
Control Range: ± 12dB
Frequency Bands: 60, 240, 1K, 3.5K, 10KHz