Sennheiser CX 400BT In-Ear Truly Wireless Headphones are the best. on a single charge, these Wireless buds last more than 7 hours and if you carry its charging case you will get extra 9 hours and it only takes 2 hours to recharge this charging case again. Via this bud, you can attend calls, as it has an integrated microphone. The best part about this Sennheiser CX 400BT In-Ear Truly Wireless Headphones is that it is super-duper light in weight, you can wear it the entire day without any effort. In this bud there’s a Built-in equalizer as well, that will equalize all the songs automatically. with this bud you will get 4 ear adapters as well, you can choose any one adapter as per your size.