For sale is a used PreSonus Eris E44 Dual 4.5-inch Powered MTM Studio Monitor. Fully functional and comes with power cord + bonus ProPod Lite acoustic speaker decouplers.

From the manufacturer:
"The Eris® E44 studio monitor delivers an expanded, highly accurate frequency response and the widest stereo field available in its class. Its nested Midwoofer-Tweeter-Midwoofer (MTM) configuration offers improved off-axis response and spatial resolution. The result is a more consistent listening experience, smoother frequency response, and an ultra-wide, detailed stereo soundstage.

Conventional two-way speaker designs can cause significant early reflections from their surrounding environment. The Eris E44 studio monitor overcomes this by positioning a 1.25-inch, silk dome, high-frequency driver between two 4.5-inch midrange drivers that cover the same frequency range.

The combined signal of the two relatively small drivers propagates forward like a single waveform, behaving like a single, larger driver. This mutual coupling provides a highly dynamic output in a compact footprint resulting in size-defying bass reproduction. At the same time, the two smaller woofers work in parallel to partially contain the dispersion of the tweeter, minimizing phase displacement. The result is incredibly detailed stereo imaging.

Like all Eris studio monitors, the E44 offers flexible connectivity and extensive acoustic tuning controls. The three-position Acoustic Space switch plus High and Mid controls help to mitigate room anomalies. A Low Cutoff filter makes it easy to integrate a Temblor® subwoofer into your monitor setup."