【Bluetooth 5 Technology】Equipped with large 40mm drivers to enhance sound resolution and achieve balanced high-quality sound reproduction from rich low frequencies to clear mid-high frequencies, ensuring clear call quality. 【High Airtightness】The ear pad surface is made of soft synthetic leather, and the inside uses a polyurethane cushion to improve stability during wear. The size that wraps around the ears provides comfortable wearing and high airtightness. Furthermore, the headband is adjustable in length, allowing you to enjoy sound with an optimal fit. 【18 Hours of Continuous Playback】With a built-in 400mAh battery, you can enjoy approximately 18 hours of continuous playback on a single full charge. You can enjoy music with peace of mind even during long hours of use. You can check the battery level of the earphones themselves on connected iOS devices (iPhone, iPad, iPod, and other Apple products). (※Only compatible with devices running iOS 6 or later) 【Wireless/Wired Dual Use】With an AUX port, you can also use a wired connection with the included cable, even on devices that do not support Bluetooth. Even if the headphone battery runs out, you can use it as a regular headphone with a wired connection, allowing you to enjoy music without worrying about the battery running out during long hours of use. Product Specifications Technology: BT5, A2DP, AVRCP, HSP, HFP Chipset: QCC3003 Driver Diameter: 40mm Speaker Sensitivity: 117dB ±3dB Speaker Frequency Response: 20Hz – 20kHz Impedance: 32 ohm ±15% Microphone Sensitivity: -42dB ±3dB Microphone Frequency Response: 50Hz – 16kHz Input: DC 5V Charging Time: 2.5 hours Continuous Usage Time: 18 hours Battery: Lithium Polymer (400mAh) Operating Range: Up to 10m Weight: 220g 【Please Read Before Purchasing】The package contents of this product do not include a headphone storage case. Please note that there was an error in the package contents listed in the instruction manual. aukey Wireless Earphones Wireless Headphones