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White ear-clip headphones with foam cushions and a 3.5 mm plug

Koss

Koss KSC21W ear-clip headphones white 3.5 mm 36 ohm 50 Hz-18 kHz

SKU CH-Z1RT-01R0Q MPN KSC21W

Ear-clip headphones with a 3.5 mm jack, 36 ohm impedance and a 50 Hz to 18 kHz frequency range

  • TypeEarphone
  • ColorWhite
  • Input Impedance36 ohms
  • ConnectorMini-phone
  • Ear CouplingOver-the-ear
  • Cord Length4 ft
  • Supra-aural fit stays comfortable through long sessions
  • Stereo drivers reproduce distinct left and right channels
  • Frequency response 50 Hz to 18 kHz covers deep bass to clear treble
  • Over-the-ear clips keep headphones secure while letting you hear surroundings
  • 5 mm plug connects directly to computers, tablets and music players

Open-ear clip headphones

The Koss KSC21W uses a lightweight ear-clip design that rests on the ear rather than sealing the canal, so you hear music and ambient sound together. Weighing only .1 of a unit, it suits commuters, office workers and anyone who wants to stay aware of surroundings while listening.

36 ohm impedance and passive operation

With a 36 ohm impedance the headphones draw minimal power from any 3.5 mm source, requiring no battery or amplifier. The four-foot cord delivers a purely analogue signal, so there is no wireless latency, pairing hassle or charging routine to manage.

Foam cushions and pivoting ear plates

Soft foam pads and pivoting plates adapt to different ear shapes, keeping pressure low during long sessions. The open, hear-through tuning lets conversation and announcements pass naturally, while the 50 Hz-18 kHz range covers bass fundamentals through treble detail.

Highlights

  • Supra-aural fit stays comfortable through long sessions
  • Stereo drivers reproduce distinct left and right channels
  • Frequency response 50 Hz to 18 kHz covers deep bass to clear treble
  • Over-the-ear clips keep headphones secure while letting you hear surroundings
  • 5 mm plug connects directly to computers, tablets and music players

Specifications

BrandKOSS
ModelKSC21
TypeEarphone
ColorWhite
Input Impedance36 ohms
ConnectorMini-phone
Ear CouplingOver-the-ear
Cord Length4 ft
Weight0.1
Shipping weight0.05 kg
Package size152 × 69 × 30 mm

Questions about this item

How do I install the Koss KSC21W ear-clip headphones, and which step is often missed?

Plug the 3.5 mm mini-phone connector into the device jack; the step often missed is adjusting the pivoting ear plates so the foam cushions sit securely over each ear for the open, hear-through fit.

What maintenance or replacement will the KSC21W need over time?

The foam ear cushions will compress and degrade with extended use; replacing them restores the original comfort and the open sound signature of the over-the-ear design.

What limit appears first during sustained listening with the KSC21W?

The 36 ohm input impedance combined with the 50 Hz low-frequency limit means bass-heavy material at high volume will reach driver excursion limits before the 18 kHz treble range becomes an issue.

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