If you want open-ear sports headphones with a stated 6–10 hours of listening per charge, choose KOAIEZ IP7; if you need headphones designed for swimming with built-in MP3 storage, choose KOPIDOE Swimming Headphones Underwater. For library use, I’d lean toward KOAIEZ IP7 for its longer stated listening range, while KOPIDOE makes more sense when swimming is the priority.
• KOAIEZ IP7’s strength: Open-ear bone-conduction design, Bluetooth 5.3, and a stated 6–10 hours of listening after a two-hour charge. Trade-off: It has no built-in MP3 storage for phone-free listening underwater.
• KOPIDOE’s strength: IP68 waterproofing and 32GB of built-in storage for MP3 playback while swimming. Trade-off: Bluetooth does not work underwater, so you must switch to MP3 mode in the pool.
• KOAIEZ IP7 suits: People who want open-ear headphones for workouts, calls, or listening around everyday activity.
• KOPIDOE suits: Swimmers who want to leave their phone poolside and listen from the headphones’ built-in storage.
KOAIEZ IP7 is an open-ear, bone-conduction sports headset with Bluetooth 5.3. Rather than filling the ear canal like a conventional earbud, it sends sound through contact near the cheekbone. That design keeps the ears uncovered, which may suit someone who wants to hear some of their surroundings while listening. It is a practical distinction for walking, cycling, or exercising where awareness of nearby activity matters.
The silicone components and rubber-wrapped neckband are intended to sit comfortably and stay in place. The headset loops over the tops of the ears, while the flexible neckband rests behind the head. That arrangement is designed for movement, not just stationary listening. KOAIEZ also lists a transmission range of 10 metres and support for multi-pairing, so it may suit someone who switches between compatible devices without wanting a fully enclosed headset.
The stated battery life is 6–10 continuous hours, with a two-hour charge. That gives the IP7 a clear use case for a workout, commute, or several listening sessions during the day, though the listed range is not a promise of the same runtime in every situation. The product information also describes IPX7 waterproofing and a built-in microphone for calls. Those features make it more relevant to active use than a basic library-only headset, but the data does not specify a separate swimming MP3 mode or onboard music storage.
For quiet study, open-ear construction may feel less isolating than closed earbuds: it leaves the ear canals open, but it does not promise noise cancellation. Someone searching for sweatproof headphones for library use may appreciate the sport-focused design, though the IPX7 rating should not be mistaken for a claim that the headphones include phone-free underwater playback. For earphones for library listening, the more important question is whether open-ear sound suits the room and whether the stated battery range covers the person’s study routine.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-23 · 9 min read · Independent comparison
Who should skip it: Skip KOAIEZ IP7 if you need built-in music storage for swimming or headphones specifically described as fully submersible at IP68.
KOPIDOE Swimming Headphones Underwater: Who It's For
KOPIDOE is the more specialized choice. It pairs an open-ear bone-conduction design with an IP68 waterproof rating and 32GB of built-in storage. The key detail for swimming is the operating mode: Bluetooth does not work underwater, and the product says to switch to MP3 mode before swimming. In practical terms, you can load music onto the headset and listen without bringing your phone into the water.
Bluetooth 6.0 and dual-device pairing are listed for use when a phone or other compatible device is nearby. But the swimming mode distinction matters more than the version number: a stable Bluetooth connection cannot provide underwater playback when Bluetooth itself does not work underwater. For a swimmer, MP3 mode is the useful feature; Bluetooth is for listening outside the water.
KOPIDOE also lists magnetic charging and describes the headset as lightweight, with clear audio. No specific charge duration or number of listening hours is given, so shoppers who need a dependable all-day runtime should not assume one from the general battery-life description. It is best understood as a swim-focused headset with a useful phone-free mode, rather than as the obvious choice for long library study.
Who should skip it: Skip KOPIDOE if you need a stated battery runtime for long study days or expect Bluetooth streaming to continue while you are underwater.
• Best for swimming with music and no phone in the water → KOPIDOE. Its IP68 rating and built-in 32GB storage are the clearest fit for that job, provided you switch to MP3 mode.
• Best for Bluetooth listening outside the water → KOAIEZ IP7. It uses Bluetooth 5.3, and its stated 10-metre transmission range may suit listening with a compatible device nearby.
• Best for a stated battery-life range → KOAIEZ IP7. The listed continuous listening range is 6–10 hours, with a two-hour charge.
• Best for adjustable fit with a swim cap or hat → KOPIDOE. Its adjustable headband is described as compatible with both.
• Best for multi-device pairing → Either, with different details. KOAIEZ lists multi-pairing; KOPIDOE specifically lists simultaneous connection to two devices.
• Best for open ears during everyday activity → Either. Both use open-ear bone-conduction designs, but neither product sheet claims noise cancellation.
• Best for library listening when battery details matter → KOAIEZ IP7. Its stated runtime gives you more to plan around; KOPIDOE does not provide a specific number of listening hours.
• Best when you need underwater playback → KOPIDOE. Its Bluetooth connection is not the underwater option; use the built-in MP3 mode instead.
Buying Considerations
First, decide where you will listen most. The two products share an open-ear bone-conduction approach, but their strongest use cases differ. KOAIEZ is framed as a sports headset for activities such as running, cycling, gym workouts, hiking, and calls. KOPIDOE is built around swimming, with IP68 protection and stored MP3 playback for use underwater.
Think about how you use a phone during listening. KOAIEZ’s Bluetooth and microphone make it relevant for calls and everyday wireless listening. KOPIDOE’s built-in storage is more useful when the phone must stay out of the pool. Its Bluetooth 6.0 and dual-device pairing apply to compatible listening situations outside the water, not to underwater streaming.
Fit and sound expectations matter, too. Both leave the ear canals open, which can help you remain aware of nearby activity, but neither sheet describes active noise control. That may suit someone who wants to hear the environment; it may be less suitable for blocking chatter in a busy study space. For library use, consider whether you need openness or isolation before choosing either design.
Finally, check what is and is not specified. KOAIEZ provides a 6–10-hour listening range and a two-hour charging time. KOPIDOE describes long battery life and magnetic fast charging but gives no numeric runtime in the supplied details. If a particular daily schedule depends on a precise number of hours, KOAIEZ offers the clearer planning information. If your key requirement is listening in the pool, KOPIDOE has the more relevant feature set.
In my opinion, I’d choose KOAIEZ IP7 for library listening because it has a stated 6–10-hour battery range and Bluetooth 5.3 for ordinary wireless use. Open ears are not the same as noise isolation, so I would pick it only if that style suits the library and its surroundings. For swimming, I’d choose KOPIDOE instead: IP68 protection and MP3 playback address a need KOAIEZ does not specify.
If your main goal is a best long battery life bluetooth headset for library search, KOAIEZ is the more straightforward match on the information provided. Its 6–10-hour range is explicit, and its two-hour charging time gives a clearer sense of what a recharge involves. KOPIDOE may still work for listening outside the pool, but its sheet does not give a comparable runtime figure.
Neither product should be treated as a sound-isolating library headphone based on the supplied features. Both keep the ear canals open, and KOPIDOE specifically describes its design as allowing awareness of surrounding sounds. That can be helpful when you need to hear announcements or conversations, but it also means these are not described as headphones that block out a room.
FAQ
No. The product information says Bluetooth does not work underwater. Switch to MP3 mode before swimming to listen to music stored on the headset.
For someone who wants a stated listening duration, KOAIEZ IP7 is easier to assess because its listed battery range is 6–10 hours per charge. Both designs are open-ear, so neither is presented as a way to block library noise.
Its stated continuous listening range is 6–10 hours, and the listed charging time is two hours. Whether that covers a particular study day depends on how long you listen and whether you can recharge between sessions.
KOPIDOE is the more clearly swim-focused option in these specifications: it lists IP68 waterproofing, built-in 32GB storage, and MP3 playback for underwater use. KOAIEZ lists IPX7 waterproofing, but its details do not describe underwater MP3 listening.
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