Question 1: Why the earbuds unable to fit well and keep falling out? Answer: Please choose your best fit eartips, it comes with 4 different size for universal fit. Put the earbuds into ear with the sound hole facing down, and rotate backwards till a comfortable angle. For more details please refer to the quick guide attached. For any assistance, feel free to contact our customer service team. Question 2: Why one earbud can not turn on/can not be charged? Answer: Dry completely with dry cloth or paper towels before placing in the charging case, paying particular attention to the charging connection points. It may cause recharging issues when the sweat or water remaining in the device. Question 3: Why hear the sound from one side only? Answer: The reset function is very helpful to ensure two earbuds work together all the time. If the earbuds have been connected with too much devices, it may cause memory confusion and one of the earbuds fails to pair, the following reset step will fix it easily. Step1: Before resetting, delete/forget all TOZO records on Bluetooth, and turn off Bluetooth as well. Step2: Press both earbuds? button for 5 seconds to turn off. Step3: Seconds later, press both buttons simultaneously for 15 seconds until purple light flashes three times, reset completed. Please restart connect the [TOZO T10-R]. Question 4: Could I use the wireless earbuds for swimming? Answer: Waterproof means it is waterproof in daily use (e.g. sweat, rain,shower). Not suitable for underwater swimming. Please note that the Bluetooth signal of the mobile phone cannot be transmitted underwater. What?s in the Box: 1 Pair of Wireless Earbuds 1 x USB Cable 1 x Charging Case 8 x Ear Caps (two are equipped on the earbuds) 1 x Quick Start Guide 1 x Product Manual