Proker via Amazon offers its Proker Wireless Bluetooth Headphones for $39.99. Coupon code "7WFFLMC5" drops it to $27.99. With free shipping, that's tied with our mention from three weeks ago, $42 off, and the lowest price we could find. They feature Bluetooth 4.2, up to 2.5 hours of playback, and compatibility with iOS or Android devices. Deal ends December 30.