After I bought it, it stopped working within a couple of months, I got a replacement (had to wait like two weeks) and I barely used it and it stopped working within a few months again, this time they refused to honor the warranty (after 6 months of the ORIGINAL purchase). The quality of the sound in the water is not very good.

Stay away.

Would need to be bit longer for my head and bit different shaped around ears for optimal comfort / conduction sound quality. Squeezes on big ear and takes getting used to.

That being said these have gotten 8h+ daily use for a month.

Good for prolonged use as ears stay ventilated as opposed to over the ear / in the ear headphones that tend to get sweaty. Also good for training / physical work as these have no problem with getting sweaty.

Swim use needs loudest volume as else the bubble noise tends to make audiobook, that i've sped up 100% with audacity, hard to follow even with the provided silicone earplugs.

Silicone plugs seem to work better than foam ones when working with power tools and listening to podcast.

Bone conduction is winning choise in many applications even with limited sound quality the method can offer.

I ordered swimming headphones 3 weeks ago.(runner diver) I have seen tests from YouTube clips in Thailand that it is waterproof. It appears that it cannot be turned on and off for the next 3 days. After trying to fix it myself for several days it's without success, I reported the problem to the Nank's website. A company representative has informed us that an improved version of the headphones for swimming will be sent as compensation. I was quite surprised that I would have to pay more or not but the company representative said that there was no need to pay more. After another 10 days, I actually received the new headphones and was very satisfied and amazed at the speed of solving problems for the nank's customers. I am satisfied and impressed with how quickly the problem was solved for a customer from Thailand like me.I don't feel like I had the misfortune of buying a broken headphones because the newer headphones provide the best sound quality i've ever heard. Thank you Nank.

I had previously purchased the first-generation Runner Diver, but it seemed to have some waterproofing issues. After using it for swimming three times, it failed to power on. I contacted customer service manager, Sean, who promptly arranged a complimentary replacement with the Runner Diver2. I have been using it for swim training for two months now, and so far, it has performed admirably. I highly commend their practice of promptly improving product quality.

By the way, there was a small incident: while swimming in TF mode, the headphones kept notifying of Bluetooth connections and disconnections. Sean explained that this was to ensure an immediate connection when switching to Bluetooth mode. The solution was to press and hold the power button for 5 seconds to start the headphones. This way, they wouldn't reconnect to previously paired devices, allowing me to use TF mode for swimming without interruptions. In conclusion, I am very satisfied with NAENKA upgrade to the headphones!

The audio clarity is remarkably vivid, even underwater, delivering my preferred melodies with sharp precision.

One standout attribute is their comfort – no more bothersome earbuds slipping out or becoming waterlogged. The bone-conduction technology is a game-changer, enabling me to enjoy music while staying attuned to my surroundings, enhancing safety during swims.