Monster Open Ear AC210 Bluetooth 5.4 Headphones $20 at Amazon $20 $70 Amazon with Direct-sale store has the Monster Open Ear AC210 Bluetooth 5.4 Headphones (White) on sale for $20 with free shipping on $35+ or with Prime. 6 hour playtime + additional 24 hours with charging case. $20 retail: $70 Posted by DrBatman05/27/2026 at 06:00 PM PT