Tusbiko via Amazon offers its Tusbiko Mini Bluetooth Wireless Earbuds in Black for $39.99. Coupon code "7HOFRHI4" knocks it to $19.99. With free shipping, that's $3 less than the best price we could find for a similar pair. These IPX7 waterproof earbuds feature up to four hours of talk/listen time after a 1-hour charge. Deal ends July 20.