Item Number:-L21 Wireless Type: bluetooth Wireless Headset Version: V5.0 Style simultaneous connection of two phones no Specification Waterproof: Yes Music listening time: about 4 hours Charging time: about 2 hours Standby time: about 120 hours Process Material: ABS Silicone Cap Battery Type: Li-Polymer Battery Supporting Agreement: HEP / HSP / A2D / AVRCP Headphone Battery Capacity: 3.7V 50mAh Battery capacity: 3.7 V 300 mAh Communication distance: 10 meters (without obstacles) Function: For Mobile Phone, Hifi Headphone, For iPod Charging case: 5-6 times (both earphones) Size: about 2mm * 16mm * 14mm / 0.08 * 0.63 * 0.55in Charging Case Size: About 28mm x 64mm x 42mm / 1.10 * 2.52 * 1.65in