【FIRST EVER EARPHONE WITH SD CARD SLOT】Directly tune to your favourite songs via the built in SD Card feature. Put the SD Card filled with your favourite songs and enjoy the workouts or work from home sessions. 【HD STEREO SOUND】With 10mm dynamic drivers, the earphone provides the perfect HD and bass+ sound effect and better listening experience for intensified workouts. 【THE MOST ADVANCED BLUETOOTH 5.0】Adopted Bluetooth 5.0 technology with noise isolation this version for better, stable and faster connection. Enjoy upto 20m range with Bluetooth 5.0 【MULTIPLE CONNECTION TECHNOLOGY】Active Switch Between Work & Play. Got a call on the phone while watching a movie on the laptop? Stay connected with two devices at once, and enjoy active switching between them automatically. 【HANDS-FREE CALL WITH NOISE ISOLATION】Fire-Boltt wireless earphones perfectly isolate ambient noise while you are talking, ensuring crystal-clear voice calls. 【COMFORTABLE & STABLE】The headset is lightweight and ergonomic design fits perfectly into the ears and can be used for extensive workouts too. 【SUPPORTS VOICE ASSISTANCE】 Go Hands-free. Works with the voice assistant on your device, so you can get things done as you stay on the go!