True Wireless Bluetooth Headset Talk 4h (24h with charging case) ANC Enco W51. Oppo's latest True Wireless headphones are called the Enco W51. The Earbuds are compatible with Android and Apple devices, and have excellent protection against sweat and splashing water thanks to their IP54 rating. The Oppo Enco W51 feature a 7mm dynamic driver for an enhanced bass experience, and their touch controls let you answer calls, change songs, and adjust volume.Each earbud has a 25mAh battery with up to 4 hours of playtime on a single charge. The charging box has a battery capacity of 480mAh, providing an additional 20 hours of battery life. Thus, the Oppo Enco W51 can be used for up to 24 hours before a trip to the wall outlet, power bank, or a Qi wireless charger is required.The Oppo Enco W51 high-quality headphones are wireless and provide users with a clear and seamless listening experience. They support a frequency range of 20 Hz to 20 kHz and use the new low-latency Bluetooth Dual-Pass, which helps reduce transmission delay. The Enco W51 have a low latency of 94ms for both ears and 47ms for a single ear. The in-ear headphones can reduce noise by 35dB with two microphones. For phone calls, Oppo Enco W51 use three microphones for noise reduction, and in total, each earphone has six built-in microphones.Oppo Enco W51 support touch function. The touch area is located on the sidebar of the earphones, and you can either answer/end calls or control your favorite music. The ultra-lightweight Enco W51 are IP54 certified, making them dust and waterproof - perfect for working out at the gym or outdoors without a worry.