All photos are the actual pedal. No box or manuals.
From BSRI Audio:
Hydrazine is a modern interpretation of the Interfax Harmonic Percolator with updates to give players a wider range of tones and textures. The core amplifier circuit has been modified for improved clarity and punch with period-correct NOS germanium and silicon transistors and germanium diodes. The active tone stack provides ample range in the bass and treble frequencies for shaping the distorted tone to meet the needs of both guitar and bass players. Finally, a unique Texture controls allows for continuous adjustment of the clipping threshold for a wide range of tones between transistor overdrive and compressed full diode clipping distortion.