Stoon V4.1 Wireless Stereo Bluetooth Headset Earphones Sweatproof In-Ear Noise Cancelling Headphones with Microphone for Running & Sports Earbuds for Smart Phones(Green) Clear bass resonance with CVC6.0 noise reduction Works Up to 5 hours, Charging time: 2 hours Bluetooth V4.1: Strong and stable wireless signal Includes a 45 days money-back & 18-month worry-free warranty