Astell&Kern Layla in-Ear Monitors by Jerry Harvey Audio - 12 Drivers per Channel, 4th Order Crossover, and Carbon Fiber Housing GREAT SOUND QUALITY WITH APTX+: high-fidelity stereo sound quality with aptx codec and CSR8645 chipset. These headphones are compatible with most smartphones, iPhone and Android. THE BEST BATTERY IN THE CLASS WITH UP TO 12+ HOURS PLAYTIME - New 2018 updated battery of 170mAh - provides Longest PlayTime Up to 12+ hours of continuous talking / music time and up to 240 hours of standby with a single charge for best sport or other experience, so you can enjoy long lasting music and less time charging. Wherever your day takes you, ELZU keeps your music. MORE STABLE CONNECTION WITH NEW BLUETOOTH 4.1 TECHNOLOGY: Compared to Bluetooth 3.0, 4.0, the latest version features faster & stable signal transmission, clearer sound quality and lower power consumption. FULLY WATERPROOF IPX7 PROTECTION - new wireless earbuds upgraded IPX7 sweatproof rating, prevent the headphones damaged from ordinary splashing water and rain. Keep the earphones working well no matter youre getting drenched in sweat after a grueling workout. SATISFACTION GUARANTEED + CUSTOMER SUPPORT 24/7: Our team of professionals is constantly working to make you happier with your decoration. We are confident in the quality of our product and give you a 100% money back guarantee within 30 days and great customer support.