How We Research
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want a wired, work-grade headset with active noise cancellation and a boom-style remote for clear calls, choose EPOS C1; if you need adjustable, open-ear earbuds that rotate to fit almost any ear and run all day on battery, choose TOZO O2.
• EPOS C1 — biggest strength: A wired USB-C headset built for the workplace, with active noise cancellation, an exceptionally noise-reducing mic, and a lightweight 63 g on-ear design meant for long sessions.
• EPOS C1 — biggest trade-off: It's wired and it's not adjustable in the fit sense — no swivel or angle tuning, and no battery to fall back on. You're tethered to your device.
• TOZO O2 — biggest strength: A dual-axis, multi-angle open-ear design that adjusts horizontally and vertically to adapt to a wide range of ear shapes, plus 42 hours of total playtime.
• TOZO O2 — biggest trade-off: Open-ear means you trade isolation for awareness. There's no active noise cancellation for listening — only DSP call noise cancellation on the mic side.
• Who EPOS C1 is for: Anyone at a desk — hybrid worker, student on a Chromebook, call-heavy professional — who wants consistent wired audio and a mic that shuts out the room.
• Who TOZO O2 is for: Runners, drivers, gym-goers, and anyone who wants adjustable, pressure-free earbuds that stay put and let traffic or a colleague's voice through.
The EPOS C1 is unapologetically a work tool. It's a wired USB-C headset with a 20 Hz–20,000 Hz dynamic driver, 22 ohm impedance, and 110 dB sensitivity — numbers that point to an easy-to-drive, consistent sound signature that doesn't need a headphone amp or a battery to perform. The enclosure mixes metal and plastic, and the on-ear/over-ear pads are designed for extended wear. At 63 g, it's light enough that a full workday or a long class block shouldn't feel like a burden.
Who should buy it: the desk-bound worker who wants one cable, zero pairing, dependable mic clarity, and a two-year manufacturer warranty backing the purchase. Who should skip it: anyone who needs to move around freely, wants adjustable fit tuning, or expects wireless freedom. The C1 is wired via USB-C, so if your device only has USB-A or a headphone jack, this isn't the plug for you. If that describes you, the TOZO O2 is the more adaptable pick.
TOZO O2: Who It's For
The TOZO O2 flips the whole premise. It's an open-ear wireless earbud built around adjustability and comfort. The headline feature is the dual-axis design — horizontal and vertical adjustment that lets you angle each earbud to sit naturally against your ear. That's the "adjustable" part buyers care about, and it's the reason these can suit a wide range of ear shapes without the pressure of a sealed in-ear tip. They're light enough, per the design intent, that you're meant to forget you're wearing them.
Sound comes from a 14.2 mm dynamic driver paired with TOZO's ORIGX acoustic tech, tuned to compensate for the open-back structure with deeper bass and clearer mids and highs. Impedance is 16 ohm and the frequency range matches the C1 at 20 Hz–20,000 Hz. Bluetooth 5.3 handles the connection, with dual-device pairing so you can run two phones and switch between them, plus single-earbud use when you only want one side in.
Side-by-Side: Which Should You Choose?
• Best for adjustable fit → TOZO O2. The dual-axis, multi-angle design is the entire point of the O2.
• Best for noise cancellation while listening → EPOS C1. Active Noise Cancellation is on the C1; the O2 only cancels noise on calls.
• Best for battery life → TOZO O2. Up to 42 hours total versus a wired headset that never needs charging but never leaves the cable.
• Best for call clarity in a loud room → EPOS C1. Its mic is purpose-built for noise reduction, backed by ANC.
• Best for workouts, running and driving → TOZO O2. IPX6 water resistance plus open-ear awareness is the safer, sweat-proof combo.
• Best for Chromebook and desktop work → EPOS C1. Chromebook certified, USB-C wired, inline volume buttons, no pairing.
• Best for multi-device switching → TOZO O2. Dual connectivity lets two phones run at once.
• Best for all-day desk wear without charging → EPOS C1. At 63 g with a metal-and-plastic build, it's built to sit and stay.
In my opinion, the EPOS C1 is the better buy for anyone whose headphones live at a desk. The combination of active noise cancellation, a noise-rejecting mic, wired USB-C reliability, and Chromebook certification is hard to beat for calls, classes, and focused work — and the two-year warranty is reassuring.
But if your day involves movement — running, driving, the gym, or just not wanting your ears plugged — I'd pick the TOZO O2. The adjustable dual-axis fit and 42 hours of battery are exactly what that lifestyle needs. Match the product to how you actually use it, and check the current price on Amazon before you commit.
how to adjust headphones on iphone
Open Settings, then Bluetooth, and tap the info icon next to your connected device to rename it or check its options. For volume and playback, use the Control Center or the inline/app controls your headphones provide. The TOZO O2 adds physical angle adjustment on the earbuds themselves, which you do by hand, not in software.
how to adjust headphones
Fit adjustment is physical: rotate, tilt, or reposition the earpieces until they sit comfortably and seal or rest as intended. The TOZO O2 uses a dual-axis design so you can adjust both horizontally and vertically. The EPOS C1 is a fixed on-ear/over-ear shape, so you adjust it by sliding the headband and positioning the pads rather than rotating the earpieces.
how to adjust headphones volume
With the EPOS C1, volume runs through the inline remote's button controls on the cable. On the TOZO O2, you use the earbud controls or your paired phone's volume, and the TOZO app lets you adjust EQ presets if you want to change the tone rather than the level.
how to adjust headphones sound
Sound shaping for the TOZO O2 happens in the TOZO app, which offers five preset EQ settings for different genres and scenarios. The EPOS C1 doesn't list app-based EQ; its tuning is fixed around its dynamic driver and 22 ohm impedance, so you'd adjust sound through your device's own audio settings.
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