MXR Stereo 15 Band Graphic Equalizer Model 127

The MXR Model 127 is a vintage, dual-channel, 15-band graphic equalizer designed for professional studio and live sound applications, featuring 1/4-inch TRS/TS inputs and outputs, rackmount compatibility, and a gain range of ±12dB per band. It was manufactured in the United States, predominantly in black and blue finishes, and was built with rugged construction for heavy use. 

Key Specifications 
Model: M-127 or Model 127
Type: Stereo/Dual-Channel Graphic Equalizer
Number of Bands: 15 per channel
Gain Range: ±12dB per band
Inputs/Outputs: 1/4-inch phone (TRS/TS) jacks
Form Factor: 19-inch rackmount unit (2U height)
Construction: Rugged, professional-grade
Origin: Made in the United States
Typical Era: 1970s-1980s

Key Features
Dual-Channel Design: Allows simultaneous processing of two separate audio signals. 
Precise Control: Offers graphic equalization for precise sound level adjustments. 
High Slew Rate: A "high" slew rate is mentioned in one source, though the specific unit isn't given. 
Robust Build: Built for studio and live sound reinforcement, indicating durability.