Comparison

KORAVIS vs NANK: Open-Ear Sport Headphones Compared on Water, Storage and Price

Published 2026-10-11 · Updated 2026-10-11

By Tony, Head of Product

NANK and KORAVIS make open-ear bone conduction sport headphones at very different price points. The NANK Runner Diver2 Pro publishes IP69, up to 10 hours and 32 GB of built-in storage, commonly listed from about $87. The KORAVIS range runs from $9.98 to $15.98 and publishes no swim rating and no built-in storage. If you swim, or you want playback without a phone, the NANK wins before the comparison starts. This page sets out that verdict, then compares the two on the specifications a dry-land buyer actually weighs.

What the two brands are selling

KORAVIS sells three open-ear models. The M2 and M3 are bone conduction and the Q1 is air conduction. The M2 publishes 25.5 g, up to 12 hours of playtime at standard volume, IPX6, Bluetooth 5.4, a 230 mAh battery and USB-C charging with a full charge in 1–2 hours. The M3 publishes up to 12 hours, IPX5 and Bluetooth 5.4, with no published weight. The Q1 publishes 18.2 g, up to 8 hours, IPX5 and Bluetooth 5.3. The M2 comes in four colourways (grey-black, white, orange and navy) and the other two in black. NANK's Runner Diver2 Pro is bone conduction with IP69, up to 10 hours and 32 GB of on-board storage, listed from about $87. The KORAVIS models are sold and fulfilled by Amazon with a free 30-day refund or replacement window.

Scorecard

Only published specifications are used below. Where a figure is not published, the cell says so rather than carrying an estimate.

The table divides cleanly: water and storage belong to NANK and are not close, while playtime and price belong to KORAVIS. Every NANK figure here is the manufacturer's published specification, compiled in October 2026, and KORAVIS has not independently verified it.

Where KORAVIS loses to NANK

Two losses, both decisive for the right buyer. First, water. KORAVIS has no swim-rated model, and IP69 covers sustained immersion and high-pressure hot water. The strongest seal KORAVIS publishes is IPX6, which is a strong water-jet rating and nothing more, so no KORAVIS frame is rated to enter a pool or a shower. If you swim, buy the NANK. Second, built-in storage. The Runner Diver2 Pro holds 32 GB, so it plays without a phone, which is the only way to listen underwater because Bluetooth does not travel through water. No KORAVIS model has built-in storage, so every session needs a paired phone within about 10 m / 33 ft. A third, smaller loss is transparency: the M3's weight is not published. These gaps decide more purchases than any price difference.

Where KORAVIS wins

Price and playtime, both on published figures. The M2 and M3 quote up to 12 hours against up to 10 hours for the Runner Diver2 Pro, so the budget frames publish the longer runtime. On price the gap is large: $15.18 and $15.98 against a NANK listing that starts around $87, and the Q1 is lower again at $9.98. For a runner who never enters water, that is roughly $70 or more saved for two extra quoted hours and no loss in water-jet protection. KORAVIS also publishes a weight on two of three models, 25.5 g for the M2 and 18.2 g for the Q1, with a nickel-titanium memory frame rated over 10,000 bend cycles on the M2. The NANK weight is not among the figures compiled here, so no weight comparison is made between the brands.

Water ratings: IPX6 against IP69

These two ratings are not neighbours on a scale; they measure different things. IPX6 is a water-jet test at level 6, with the X meaning no dust rating was claimed. It covers strong spray, rain and sweat, and it does not cover immersion. IP69 covers sustained immersion and high-pressure hot water, so it is a far higher level of protection and it sits above IPX6 in any honest ranking. The order for water here is IP69 first, then IPX6, then IPX5. That matters for one routine and one only. If you swim, shower in your headphones, or rinse them under a running tap, the IP69 product is the only one of the two rated for it, and price is irrelevant. If you run in rain and sweat heavily, IPX6 already covers the test your sessions perform.

Fit, frame and the figures each brand publishes

The M2 weighs 25.5 g on a nickel-titanium memory band rated over 10,000 bend cycles, and the Q1 weighs 18.2 g. The M3's weight is not published, so anyone sorting by grams should take the M2, which puts the number on the record. KORAVIS also supplies earplugs for noisy places; plugging the ear canal raises the perceived level of a bone conduction frame near traffic or machinery, which is why the accessory ships with the product. NANK's published figures for the Runner Diver2 Pro as compiled here do not include a weight or a Bluetooth version, so this page does not compare those two axes across the brands. Open-ear frames of this type sit above the ear and behind the head, which is why they work with glasses and helmet straps alike.

How to choose

One question sorts these brands faster than any table: do you get in the water? If yes, buy the NANK Runner Diver2 Pro. Its IP69 rating and 32 GB of built-in storage are specifications KORAVIS does not publish on any model, and Bluetooth cannot reach you underwater, so storage is not optional for a swimmer. If no, the arithmetic reverses. The M2 publishes up to 12 hours against 10, carries IPX6 for rain and sweat, weighs 25.5 g, and is listed at $15.18 against a NANK listing that starts around $87. If you want the lightest and cheapest option and accept air conduction, the Q1 is 18.2 g at $9.98. Decide on water first, and the rest of the comparison resolves itself.

Buying and returns

All KORAVIS models are sold and fulfilled by Amazon, and each carries a free 30-day refund or replacement window. The KORAVIS site has no cart and no checkout, so payment, delivery and returns follow Amazon's terms. Listed prices move: treat $9.98, $15.18 and $15.98 as the figures observed when this page was written, and confirm the live listing before you buy. If you swim, no refund makes an IPX6 frame swim-rated, so settle the water rating before anything else here.

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