Features: 1. TPE medical silicone, softer, with no harm to your skin after a long time wear; 2. Dual filtration function, auto filter the noise from the environment. Make the sound clearer and more nature; 3. Big Capacity Battery, Charge For 1 Hour, Use For 48 Hours; 4. Smart Chip, no need to match anything; 5. One power button, one volume control, easy to use. 6. FCC, ROHS, CE, EMC Certifications available. .