Key Features . Hybrid Active Noise Cancellation and Triple-Mic Noise Reduction during CallsBinaural Low-Latency Bluetooth Transmission24 Hours of Music Playback ( 4 hours from single use)IP54 Dust and Water Resistance . Hybrid Active Noise cancellationThe W51 come equipped with a new dual-core digital noise reduction chip and more advanced hybrid noise reduction microphones. They are intelligently optimised to detect and reduce every day noises such as from subways and trains. With a noise reduction depth of 35 dB you get an undisturbed listening experience. Triple-Mic Noise ReductionEach earphone comes equipped with triple microphone noise reduction technology and redesigned air ducts to prevent noises of wind. Whether you are in the subway on the bus or riding your bike even a single earphone will capture your voice clearly. Binaural Low-Latency Bluetooth TransmissionThe W51 adopt the newest Bluetooth low-latency binaural transmission standard to greatly reduce any audio delay. This significantly improves audio-to-video synchronisation making audio lag and signal interference no longer an issue for your music and video experience. New Quality Compensation for Professional Audio PerformanceOPPO’s first true wireless headphones to be equipped with a system-wide audio quality compensation algorithm to avoid loss of audio quality from noise reduction techniques. The W51 offer quality restoration of the audio for clean uncompromised audio performance. Additionally the headphones are equipped with Dual TPU composite graphene diaphragms to provide enhanced audio response and treble performance. IP54 Rated Dust and Water ResistanceStructurally designed and certified for IP54 dust and water resistance6. Whether it is the gym or an outdoor commute listen with peace of mind knowing your headphones are safe..