If you want over ear headphones for swimming or a secure, open-ear design that keeps you safe during outdoor activities, choose HAKII Open Ear; if you need the best bluetooth earbuds for swimming with active noise cancellation and a sealed in-ear fit, choose KDYNIX True. This isn't a tie. The choice depends entirely on whether your priority is situational awareness and a non-intrusive fit or total immersion and isolation from the world.
• HAKII Open Ear: Strengths include an ultra-lightweight 7.5g clip-on design and IPX5 sweat resistance perfect for running; the trade-off is the lack of Active Noise Cancellation and no submersion rating for actual swimming.
• KDYNIX True: Strengths feature a robust IPX7 waterproof rating for full submersion and Dual ENC/ANC technology for deep bass and silence; the trade-off is an in-ear design that blocks out environmental sound.
• Best For: HAKII is for runners and cyclists who need to hear traffic; KDYNIX is for swimmers and commuters who need to block out the chaos.
The HAKII Open Ear is engineered for people who refuse to sacrifice their connection to the physical world while they move. Its defining characteristic is the "clip-on" architecture, which sits outside the ear canal rather than inside it. At just 7.5 grams per bud, this headset feels like a whisper against your skin. The design utilizes a flexible titanium core wrapped in soft silicone, ensuring it hugs the ear securely without applying pressure. You can wear these all day without the fatigue that often plagues traditional in-ear buds.
This product shines specifically for outdoor sports where safety is paramount. Because the ear canal remains open, you can naturally hear approaching cars, other cyclists, or gym equipment without needing to remove the device. The IPX5 rating means it handles intense sweat and rain with ease, making it a reliable companion for high-intensity workouts or rainy runs. However, the open design also means there is zero Active Noise Cancellation. If you are looking for a headset for swimming, this model is not suitable because it lacks the submersion capabilities required for underwater use.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-25 · 6 min read · Independent comparison
You should buy the HAKII Open Ear if you are a runner, cyclist, or hiker who prioritizes situational awareness over absolute silence. It is ideal for urban environments where hearing your surroundings is critical. However, you should skip this product if your primary goal is to drown out the noise of a busy office, a noisy commute, or if you plan to take your audio gear into the pool. The lack of ANC and the specific IPX5 rating (splash-proof, not submersible) make it a poor choice for aquatic activities.
In contrast, the KDYNIX True is built for those who demand isolation and complete audio immersion. This is a true wireless in-ear solution that uses a sealed design to block out external noise physically. The standout feature here is the combination of Dual ENC and Active Noise Cancellation (ANC). This technology actively filters out background chatter and engine hum, allowing the 13mm drivers to deliver deep, punchy bass without competition from the environment. It creates an immersive experience akin to being at a private concert, regardless of where you are standing.
The most critical differentiator for this product is its IPX7 waterproof rating. Unlike the HAKII, which resists sweat and rain, the KDYNIX True is rated for submersion. This makes it one of the few viable options for best headset for swimming among standard consumer earbuds. Whether you are doing laps in a pool or caught in a heavy downpour, the internal electronics are protected against water ingress up to a certain depth. The single bud weighs only 0.14 ounces, and the case is compact enough to slip into any pocket, but the in-ear seal is what delivers both the sound quality and the water protection.
You should choose the KDYNIX True if your primary activity involves water or if you need to block out distractions completely. It is the superior choice for swimmers who cannot rely on an open-ear design. It is also excellent for travelers trying to sleep on planes or for office workers needing focus. However, if you find in-ear designs uncomfortable or if you dislike the feeling of having something plugged into your ear canal, this might not be for you. The sealing nature of the buds means you will be cut off from ambient noise, which could be dangerous if you are running near traffic.
• Best for Swimming → KDYNIX True: Only the KDYNIX offers an IPX7 rating capable of handling submersion, whereas the HAKII is limited to splash resistance.
• Best for Situational Awareness → HAKII Open Ear: The open-ear design allows you to hear traffic and surroundings, a safety feature the sealed KDYNIX cannot provide.
• Best for Noise Isolation → KDYNIX True: With Dual ENC and ANC, the KDYNIX actively cancels noise; the HAKII has no noise control features.
• Best for All-Day Comfort → HAKII Open Ear: At 7.5g per unit, the clip-on design eliminates the pressure and ear-canal fatigue common with in-ear models.
• Best for Deep Bass & Immersion → KDYNIX True: The 13mm drivers combined with a sealed fit deliver richer low-end frequencies than the open-air HAKII.
• Best Battery Life → HAKII Open Ear: Offers 24 hours of total playtime with the case, compared to the KDYNIX's 18-hour total capacity.
• Best for Call Clarity in Wind → KDYNIX True: The dual microphone setup with ANC provides better voice clarity in noisy environments than the HAKII's ENC.
• Best Value for Water Sports → KDYNIX True: If you swim, the IPX7 rating is non-negotiable, making this the only logical choice between the two.
After analyzing the specifications and intended use cases, I would personally choose the KDYNIX True if my goal was to find a pair of best bluetooth earbuds for swimming. The IPX7 rating is a functional necessity for anyone entering the water, and the Active Noise Cancellation adds a layer of performance that the open-ear design simply cannot match. While the HAKII is a fantastic device for runners who need to stay alert, it falls short when the environment changes from dry land to a pool. The KDYNIX covers the critical requirement of water resistance while delivering the immersive audio experience most users seek. If you are torn between staying safe in traffic or getting wet in the pool, the water capability wins every time for me.
Only the KDYNix True is suitable for swimming due to its IPX7 waterproof rating, which allows for submersion. The HAKII Open Ear is only IPX5 rated, meaning it handles sweat and rain but should not be submerged in water.
It depends on your workout style. If you run outdoors, you should skip active noise cancellation to hear traffic, making the HAKII better. If you work out indoors or swim, the KDYNIX ANC helps you focus by blocking out distractions.
The HAKII Open Ear provides 6 hours of playback on a single charge, extending to 24 hours total with the charging case. The KDYNIX True offers a total of 18 hours of battery life across the buds and case.
The KDYNIX True likely offers deeper bass due to its 13mm drivers and sealed in-ear design that traps sound. The HAKII uses 12mm drivers but relies on an open-ear design, which typically results in less perceived bass intensity.
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