https://www.cnet.com/news/just-bought-bose-quietcomfort-25-headphones-make-them-wireless-with-this-45-adapter/

It normally sells for $60, but for a limited time, you can get the AirMod QC25 for $45 shipped with promo code cybermonday.

Even with the discount, that may seem a little steep for a Bluetooth adapter. After all, you can get similar products for your home stereo for as little as $15.