ATC LLC via Amazon offers the Lumsing Bluetooth Audio Transmitter / Receiver 2-in-1 Adapter for $27.99. Coupon code "7922LHB5" cuts it to $16.99. Plus, Prime members receive free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $5.99.) That's the lowest total price we could find by $11. It easily switches between transmitter and receiver modes to interact with non-Bluetooth devices so they work with your Bluetooth speakers, headsets, cell phones, and MP3 players. It includes an RCA to stereo Y-cable, 3.5mm audio cable, and USB charging cable. Deal ends April 19.