Amazon Warehouse Deals via Amazon offers Prime members the used Sennheiser On-Ear Wireless Headphones, model no. RS120, for $28.14 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.95.) That's $48 under the best price we could find for a new pair. These open-back headphones feature a wireless transmitter that acts as the headphone charging dock and two AAA NiMH rechargeable batteries.

No warranty information is included.