The seller of this product is not affiliated with, sponsored, licensed or endorsed by any Bluetooth branded entity or service.Space level noise reduction: Switch transparency mode with just one press, the noisy map instantly transforms into a private concert24-hour ultra long battery life: Magnetic flash charging box for easy charging for 10 minutes and 2 hours of smooth listeningErgonomic design: Liquid silicone earplugs can't be shaken off, making fitness commuting as stable as CPDual device instant connection: seamless switching between mobile phones and tabletsIPX5 Waterproof: Exercise, Sweat, Rainy Days, Unrestrained Use100% eye-catching fashion black technology accessories on the street The preferred gift for family and friendsWe understand that a very small number of users may experience a slight difference in volume between the left and right ear. This can usually be resolved with a simple setup or operation and is not a hardware failure of the headset. Please follow these steps to troubleshoot: Step 1: Check fit "Make sure that the left and right earphones are worn tightly and deep into the ear canal. Too shallow a fit or an incomplete seal will result in sound leakage and affect the listening balance. Try gently rotating or adjusting the angle of the headphones to find the most snug and comfortable wearing position."Step 2: Check your phone/device sound balance settings, "Abnormal sound balance settings are a common cause. Please go to your phone/device settings to troubleshoot:" General Path Guide: iOS Example: "Settings > Accessibility > Audio/Visual > Check that the left and right channel balance sliders are in the center position."Android example: "Settings > Accessibility > Listening > Check the Left and Right Channel Balance or Mono audio settings (make sure Mono is turned off)."Step 3: Swap Left and Right Ear Test "This is a critical step in determining the source of the problem!" "Swap the headphones originally worn in the left ear to the right ear, and the headphones originally worn in the right ear to the left ear.""Listen again:" "If the original 'low sound' side is now louder: This means that there is no problem with the hardware of the headphones themselves, and the problem may lie in the difference in hearing between your ears, the way you were wearing them before, or the device settings. Please return to steps 1 and 2 to double check.""If the original 'small sound' side is still small after switching ears: This means that there may be an abnormality in that headphone unit. Please proceed to the next step."Step 4: Reset the headset and re-pair "A temporary software glitch may also cause this problem. Please try: ""Put the headphones back into the charging case, close the cover and wait for more than 15 seconds."""Open the lid and long press the setup button on the back of the charging case (please refer to the instruction manual illustration for the exact location of the button) for about 10-15 seconds until the status indicator blinks in a specific way (indicating that the reset is successful)."""Forget this device in your device's Bluetooth settings.""Bring the headset close to the device and follow the initial pairing process to reconnect."Tip: "Please test the volume balance again after resetting."Step 5: Cleaning the Headphone Sound Out Holes Description: "Earwax or foreign objects clogging the sound out holes may cause sound to become muffled or distorted. Please use a dry, soft brush (e.g., eyeglass cloth, small makeup brush) to gently clean the sound holes in the metal mesh of the headphones. Do not use sharp objects or liquids for cleaning!Troubleshooting Results Guidelines: "After completing the above steps, if the problem is resolved, you can continue to enjoy your music!""If the sound from a specific headphone unit is consistently and noticeably low after completing all of the above steps (especially the third step of the swap test), a hardware problem may be involved."Hardware problem handling: "Please prepare your proof of purchase and contact our official customer service channel:" "Our customer service team will be happy to provide you with further support and handling options."Plain