Curvature Digital via Amazon offers the Mjyun Wireless Bluetooth In-Ear Headphones in Black or White for $39.99. Coupon code "W6FNXULQ" cuts that to $27.99. With free shipping, that's $12 off and the lowest price we could find. They feature Bluetooth 4.2 and a 500mAh battery charging case. Deal ends December 31.