Cellfeee via eBay offers the Boomcloud 360 Boomstick Audio Enhancer in Silver or Black for $39.99 with free shipping. That's $20 under our Black Friday mention and the lowest total price we've seen. (It's the best deal today by $20 as well.) It's compatible with most audio devices with a 3.5mm connector and is designed to enhance bass response, definition, and clarity.