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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-05 · 7 min read · Independent comparison
• Koss CS300-USB — biggest strength: It's a finished, double-sided on-ear communication headset with a noise-cancelling electret microphone, a flexible mic arm, and a single USB-A plug, so it works out of the box on any USB-equipped device.
• Koss CS300-USB — biggest trade-off: It's wired. There's no Bluetooth, no true-wireless freedom, and no battery to manage — you're tethered by the 8-foot cable.
• D & K Exclusives Replacement Foam Earpads — biggest strength: A 50-pack of soft, high-elasticity 45mm foam cushions that stretch to fit many on-ear and over-ear headsets, letting you refresh worn pads over and over.
• D & K Exclusives Replacement Foam Earpads — biggest trade-off: They're a consumable accessory, not a headset. They won't add a microphone, a cable, or any electronics — they only replace the foam already on a compatible headset.
• Buy Koss CS300-USB if you need a complete communication tool for webinars, calls, telehealth, or a call center.
• Buy D & K Exclusives Replacement Foam Earpads if you already own a compatible on-ear headset and just want to keep the cushions soft and hygienic.
The Koss CS300-USB is a dual-sided on-ear communication headset built for talking, not for music marathons. Both ears get a soft, pillow-like on-ear cushion on a lightweight frame with Koss's form-fitting D-Profile, which is the kind of spec that matters when you're sitting through a two-hour webinar with the headset on the whole time. A double-sided design means audio comes to both ears, so you hear the presenter and your own call audio in stereo rather than in one ear only.
The microphone is the real story here. It's a noise-cancelling electret mic on a flexible arm, so you can bend it toward your mouth and keep your voice consistent. The noise-cancelling element is designed to reduce ambient sound distortion, which is exactly what you want in a shared office, a classroom, or a home desk near a noisy street. The headset connects over a single-entry 8-foot cable that terminates in USB-A, and it works with anything that has a USB input — no separate mic and headphone jacks to juggle. Koss lists it for conference calls, telephony, language-learning software, listening labs, testing, gaming, and hands-free office communication, and notes it works with Dragon NaturallySpeaking. There's also an inline volume control.
Frequency response runs 20 Hz to 20,000 Hz with a dynamic driver, and the enclosure is plastic in black. The listed noise control is active noise cancellation, and the warranty is a lifetime one — a notable detail for anyone who treats a headset as a long-term desk tool.
Who should skip it: If you want to walk around during calls, this isn't it. There's no wireless mode. And if you're looking for spatial audio true wireless earbuds for webinars, or crystal clear calls true wireless earbuds for webinars with a charging case, this wired headset is a different category entirely. Same goes if you're chasing active noise cancelling head phones for webinars in the sense of music-grade ANC headphones — this is a communication headset with a noise-cancelling mic, and the ANC label applies to the noise-control spec, not to a consumer music-listening feature set.
D & K Exclusives Replacement Foam Earpads: Who It's For
These are replacement foam earpads, and it's worth being blunt about that: they are not a headset. What you get is a 50-pack of 45mm (1.8-inch) sponge cushions in black, made from a soft, high-elasticity memory foam that's lightweight and breathable. The point is comfort and hygiene over the long haul — the foam is designed to reduce ear fatigue during extended listening sessions and to spread pressure rather than concentrate it on the ear.
The second job these pads do is acoustic. The listing describes them as minimizing sound leakage and blocking ambient noise to improve clarity, which is the standard reason worn pads get replaced: when foam flattens and cracks, isolation drops and everything sounds thinner. Fresh foam restores some of that seal. Just don't read this as active noise cancellation — it's passive isolation from the material, nothing electronic.
Installation is the easy part. The stretchable design is meant to slip over the ear cup and settle into place without tools, so you can swap a worn pad in a minute or two. Compatibility is broad: D & K Exclusives names MDR-G45, MDR-222KD/PIN, PMX60, PMX100, PX100, PX20, HD15, HD36, and HD56, plus other on-ear and over-ear headphones with a similar ear cup diameter. The critical number is that 45mm measurement — if your ear cups aren't close to it, these won't seat properly.
Who should buy them: People who already own a compatible on-ear headset, especially in an office, call center, or classroom where headsets get shared and pads get grimy fast. A 50-pack turns pad replacement into routine maintenance instead of a reason to buy a new headset.
Who should skip them: Anyone who doesn't already own a compatible headset, or whose ear cups aren't in the 45mm neighborhood. And if you're shopping for a complete solution with a microphone, keep looking.
• Best for a complete, plug-and-play webinar setup → Koss CS300-USB. It's the only one of the two that's an actual headset.
• Best for microphone quality on calls → Koss CS300-USB. Noise-cancelling electret mic on a flexible arm, with reduced sound distortion.
• Best for comfort on a compatible headset you already own → D & K Exclusives Replacement Foam Earpads. Soft, high-elasticity foam aimed at cutting ear fatigue.
• Best for hygiene in shared or high-traffic environments → D & K Exclusives Replacement Foam Earpads. 50 disposable-style covers means you never run out mid-term.
• Best for connectivity flexibility → Koss CS300-USB. USB-A over a single 8-foot cable works with any device that has a USB input.
• Best for long-term ownership → Koss CS300-USB. Lifetime warranty on the headset itself, versus a limited warranty on the foam.
• Best for restoring an older headset instead of replacing it → D & K Exclusives Replacement Foam Earpads. Passive isolation and a fresh seal for a fraction of the commitment.
• Best value → it genuinely depends on what's missing. Neither replaces the other; one is a tool, one is a maintenance part.
In my opinion, if your goal is showing up to webinars with clear audio and a working microphone, buy the Koss CS300-USB. It's a complete, wired, double-sided on-ear communication headset with a noise-cancelling electret mic, a flexible boom, inline volume, and a lifetime warranty — nothing else to buy, nothing to charge. I'd only steer you to the D & K Exclusives Replacement Foam Earpads if you already own a compatible on-ear headset and want to keep it comfortable and clean with a 50-pack of 45mm cushions. For webinars specifically, the Koss is the one that actually gets you on the call.
An on-ear headset rests on top of your ears rather than surrounding them, which is how the Koss CS300-USB is built — soft pillow-like cushions sit against the ear on a lightweight frame. That makes it lighter and less bulky than an over-ear design, though it typically isolates less.
An over-ear (circumaural) headset has ear cups that fully surround the ear, which usually means more passive isolation and a bigger, heavier frame. The D & K Exclusives pads are sized for on-ear and over-ear models with roughly 45mm ear cups.
You position the single ear cup over one ear and route the boom mic toward your mouth on that same side. The Koss CS300-USB here is the double-sided version, so if you specifically want a one-ear setup you'd look at the single-sided variant instead.
If you mean opening up the ear cup to replace pads, you generally stretch the foam cushion over the rim of the cup and work it around until it seats — the D & K Exclusives pads are built with a stretchable design for exactly that. No tools are required for the swap.
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