Up for sale is a used Electro-Harmonix Micro Q-Tron Envelope Filter pedal in excellent working condition.

This classic, pure-analog auto-wah analyzes your playing dynamics to deliver highly responsive, organic filter sweeps that act as a direct extension of your style. Featuring three selectable filter modes (Low Pass, Band Pass, High Pass), a Drive sensitivity adjustment, and a Q resonance control, it allows guitarists, bassists, and keyboard players to easily dial in everything from smooth vowel tones to aggressive, hyper-funky sweeps.The pedal has been fully tested and functions perfectly; all knobs sweep smoothly, the heavy-duty switch engages firmly, and the LED status light works as intended. Visually, the pedal shows light signs of normal cosmetic wear from handling (please review the photos for exact cosmetic condition). It features a True Bypass circuit to keep your clean tone completely unaffected when turned off, and it runs reliably on a standard 9V battery or a center-negative 9V power supply.