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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-25 · 6 min read · Independent comparison
• Monster Open Ear AC210 — biggest strength: It's a complete open-ear headphone with Bluetooth 5.4, dual 12mm dynamic drivers, touch controls and up to 30 hours of total playback with the charging case.
• Monster Open Ear AC210 — biggest trade-off: It has no active noise cancellation, and the open-ear design means you'll hear your surroundings rather than being sealed off from them.
• PROfezzion Shokz OpenFit 2+ — biggest strength: A drop-proof hard shell with a secure locking latch and IPX5 water resistance that protects the Shokz OpenFit 2+ charging case from splashes, spills and drops.
• PROfezzion Shokz OpenFit 2+ — biggest trade-off: It contains no electronics. It is only a case, and it only fits the Shokz OpenFit 2+ (2025) — not the OpenFit Air or the original OpenFit.
• Who each pick is for: Buy the Monster AC210 if you need actual earphones; buy the PROfezzion case if you already own Shokz OpenFit 2+ headphones and want to protect their charging case.
The Monster Open Ear AC210 is a true open-ear headphone. That means the earpieces sit outside your ear canal instead of being pushed into it. Monster's pitch here is comfort and ear health: no pinching of the auricle, no pressure inside the ear, and sound that reaches you without plugging anything up. If you've ever given up on earbuds because they ache after an hour, this is the design philosophy aimed at you. The enclosure is built around skin-friendly silicone, and the set comes with a slim white plastic charging case that's meant to slip into a pocket.
On the audio side, the numbers are worth reading carefully. Monster uses dual 12mm dynamic drivers paired with modified PI composite beryllium diaphragms, plus a DAC sound card rated at 30mW of thrust. The claimed frequency range is 20 Hz to 20,000 Hz — the full standard audible band — and the impedance is listed at 3 ohms. In practice, specs like these describe a driver setup built to push a wide, three-dimensional stereo image rather than a thin, tinny open-ear sound. Bluetooth 5.4 handles the connection with a stated range of around 10 meters, and pairing is a simple one-click affair.
Battery life is the headline feature. Monster rates it at up to 6 hours of listening on a single charge and up to 30 hours total when you factor in the charging case. Charging is over Type-C. Controls are touch-based, and there's an IPX5 water resistance rating, which covers splashes and light rain but not swimming or full submersion. There's no noise cancellation at all — that's a deliberate consequence of the open design, and it's the reason runners and cyclists tend to like this category.
PROfezzion Shokz OpenFit 2+: Who It's For
Now let's be blunt about what this product actually is, because it's easy to misread the listing. The PROfezzion Shokz OpenFit 2+ is not a headphone. It's a case cover for the charging case of the Shokz OpenFit 2+ (2025) open-ear headphones. If you don't already own those headphones, this product has nothing to do for you — full stop. It's also specifically molded for the 2+ model and is not compatible with the OpenFit Air (2024) or the OpenFit 1 (2023).
What it does, it does with intent. The shell is a hard, heavy-duty design assembled from ABS, polycarbonate, metal, plastic and silicone, measuring roughly 3.01 x 2.81 x 1.33 inches and weighing about 0.08 kg. That combination of materials is what lets PROfezzion call it lightweight, shockproof and drop-proof while still adding real structure. The standout feature is the secure locking latch: it holds your charging case shut, so the lid can't pop open and spill your earbuds onto the pavement when you fumble it. That's a genuinely thoughtful detail for anyone who has watched a case bounce down a stairwell.
Inside, a non-slip silicone pad grips the charging case from the bottom so it doesn't rattle around. PROfezzion explicitly calls out that this design avoids the adhesive-tape approach some competitors use — tape that eventually loses its stick. The whole thing carries an IPX5 water resistance rating, which means it shrugs off splashes and spills. It also lists dust resistance and spill resistance as additional features, and it comes with a 1-year warranty description.
Who should buy it: Shokz OpenFit 2+ owners who carry their case in a bag, gym sack or jacket pocket and want it armored against drops, rain and general abuse. Who should skip it: Everyone else — and especially anyone shopping for headphones, because this isn't one.
• Best for actually listening to music → Monster Open Ear AC210. It's the only one of the two that produces sound.
• Best for battery life → Monster Open Ear AC210. Up to 6 hours per charge, up to 30 hours with the case.
• Best for protecting a Shokz OpenFit 2+ → PROfezzion Shokz OpenFit 2+. Locking latch, hard shell, full coverage.
• Best for workouts and outdoor use → Monster Open Ear AC210. Open-ear fit plus IPX5 means sweat, splashes and traffic awareness are all handled.
• Best for drops and bag life → PROfezzion Shokz OpenFit 2+. The drop-proof shell and shockproof construction exist purely for this.
• Best for comfort over long sessions → Monster Open Ear AC210. No eartip enters the canal, so there's nothing to pinch or fatigue.
• Best for calls → Monster Open Ear AC210. It lists HD clear calls and touch controls; the case obviously offers neither.
• Best for a Shokz owner who already has everything → PROfezzion Shokz OpenFit 2+. This is an accessory purchase, not an upgrade.
In my opinion, the Monster Open Ear AC210 is the one to buy for the vast majority of people landing on this comparison, because it's an actual pair of headphones with Bluetooth 5.4, 12mm dual drivers, touch controls, Type-C charging, IPX5 water resistance and up to 30 hours of total playback. The PROfezzion case is a well-considered accessory — the locking latch and non-slip silicone pad are exactly the right ideas — but it only makes sense if you already own Shokz OpenFit 2+ headphones and want to keep their charging case intact. Pick based on which problem you actually have.
are headphones waterproof
Not in the way a dive watch is. Both products here are rated IPX5, which means they resist water jets and splashes — rain, sweat, a spilled drink — but neither is designed to be submerged. If you need swimming-grade protection, IPX5 isn't it.
are headphones water resistant
Yes — and that's the correct term for both of these. The Monster Open Ear AC210 carries an IPX5 water resistance rating for the earbuds themselves, and the PROfezzion Shokz OpenFit 2+ carries an IPX5 rating for its hard shell cover. Water resistant means they tolerate exposure, not immersion.
No. The PROfezzion Shokz OpenFit 2+ is made only for the Shokz OpenFit 2+ (2025) charging case and won't fit Monster's. The Monster AC210 comes with its own slim white charging case, so there's nothing extra to buy.
I don't quote prices here because they change often — check the current price on Amazon using the button on this page. On value, it comes down to need: the Monster AC210 is a complete headphone system, while the PROfezzion case is a single-purpose protector for headphones you already own.
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See also: Tatybo Gaming Headset vs Monster Open Ear AC311, WOWRIO Open Ear vs Shokz OpenDots Air Open-Ear, Shokz OpenDots ONE Open-Ear vs Flemikie Bone Conduction Headphones