The ACEFAST N4 is a long-runtime Bluetooth neckband made for all-day listening. With a large 800mAh battery, you get up to ~130 hours of music or ~100 hours of calls, and the LED digital display makes it easy to check power at a glance. Play wirelessly over Bluetooth 5.3 or go phone-free using the built-in TF card player. A 10 mm driver handles everyday music and calls, while the IPX4 rating resists sweat and light rain. Charge via USB-C; several retailer listings note a 10-minute quick top-up for ~10 hours—great for busy days in Bangladesh.