VMInnovations offers the refurbished Sennheiser MX 680 Adidas Sports In-Ear Headphones in Yellow for $4.99 with free shipping. That's the best we could find for a similar refurb by $20. Features include a frequency response of 18Hz to 20,000Hz, 16 ohms impedance, foam ear pads, and a cable clip.

A 1-year VMInnovations warranty applies.