BT 4.2 technology offers fast transmission speed and high-quality signal. Easy to connect with BT-enabled devices. Equipped with 40mm large size drive unit, excellent titanium-plated diaphragm, bringing shocking bass and clear treble. Connect to the audio devices (such as MP3/MP4, Laptop, etc) without BT function via the 3.5mm audio cable (NOT included). Adopt a telescopic headband and suspension earmuff, which can be adjusted by up and down, fits for different head sizes. Can insert a TF card (NOT included) and work as an MP3 player. Supports FM radio function. And you can download the NI A APP for music playback and sound adjustment. Over Ear Wireless Headphones Q2 Foldable On Ear Headset Wirelessly BT Earphones 3.5mm AUX in Music Earphone TF Card MP3 Player FM Radio with Microphone APP Control