Specifications:The headphone has built-in wireless radio device.Earmuff features soft, breathable and comfortable to wear.With foldable design, it is easy to carry and store.It can be retractable to fit your size.With large capacity battery, it has 250 hours standby time.Item Name: Wireless HeadphoneMaterial: ABSBluetooth Modes: A2DP 1.2, AVRCP 1.0, HSP, HSF 1.5Frequency: 2.402-2.480GHZ, 2.4G ISM Frequency BandRF Performance: Receiving sensitivity: -84dBm, Maximum Transmit Power: 4dBmFrequency Response: 20Hz-20KHzSignal to Noise Ratio (SNR): 70dBTotal Harmonic Distortion (THD): 0.1%Power Indicator: Blue LightCharging Time: about 2.5 HoursTalk Time: up to 10 HoursStandby Time: up to 250 HoursOperating Temperature: -20-55 Degree CelsiusBattery Capacity: 400mAh (Included)Features: Wireless, Retractable, with MicSize: 19cm x 17cm x 7cm/7.48" x 6.69" x 2.76" (Approx.)Notes:Due to the light and screen setting difference, the item& 39;s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Wireless Headphone1 x USB Charging Cable1 x User Manual