Dual mode: Wireless and wired Bluetooth mode: Bluetooth 4.2 with NFC function, easy to connect to any Bluetooth device (tablet, smartphone, iPhone, iPad, iPod, PC, etc). Wired mode: Seconds to be an audio wired headset. Comfortable fit extremely soft ear muffs with memory protein ensure long-lasting comfort, soundproof design to effectively isolate 85% background noise, make you stay away from the noisy world to be yourself. Supports TF card mode Using a TF / Micro SD card with loaded MP3 music allows you to listen to the songs directly on the headphones. (TF card not included) Specifications Output power: RMS 3W x 2 Speaker: 4 Ω, 3 W, φ1.575 in Battery capacity: 400 mA Bluetooth version: 4.2 Input power: DC 5 V 500 mA Maximum current consumption: 500 mA Frequency response: 90-18 KHz Sensitvity: 500 mV ± 50 mV Signal to noise ratio: ≥70 db Distortion degree: ≤0.3 Operating time: Hold 3.5 - 7 hours of operation Charging time: about 2 hours Functions: Bluetooth / NFC / FM Radio / TF card / AUX. Warm Tips: Playback time varies by volume level, and HS3 audio content is designed based on audio structure, so the headphone cable only works while connecting before running out of battery, exactly as if an audio cable with speaker is used. 5 - 7 hours of operation Charging time: about 2 hours Functions: Bluetooth / NFC / FM Radio / TF card / AUX. Warm Tips: Playback time varies by volume level, and HS3 audio content is designed based on audio structure, so the headphone cable only works while connecting before running out of battery, exactly as if an audio cable with speaker is used. 5 - 7 hours of operation Charging time: about 2 hours Functions: Bluetooth / NFC / FM Radio / TF card / AUX. Warm Tips: Playback time varies by volume level, and HS3 audio content is designed based on audio structure, so the headphone cable only works while connecting before running out of battery, exactly as if an audio cable with speaker is used.