The description in the headline above is Klipsch's, not mine. I usually refer to this kind of product as earbuds. But Klipsch is allergic to that term for arcane technical reasons explained in this FAQ. So headphones these wispy transducers are.

The X5 is the second of Klipsch's two Image models, differing from the X10 in having a diaphragm that is 2mm smaller and, at $250, a hundred dollars less costly. Klipsch also offers three Custom models starting at $129.

If you want your phones-not-buds to be lightweight, the Klipsch Image X5 is as close to weightless as can be. The 50-inch black cord is very slender. It is also reinforced in four places—at either end, of course, but also at two points in between. One is the place where the single cord forks off into left and right channels. The other is a sliding adjuster that can be used to tighten the X5.

Fit is a perpetual concern with this kind of product. Klipsch's solution is silicon earpieces, or gels, as the company calls them. Five pair are provided—three with single flanges, and two with double flanges. All of them have a distinctive oval shape, as opposed to the typical round shape. Klipsch says this provides a better and more natural fit.

You never really know how these things will work until you try them, and with a product this expensive, that can be a nail biter. I can only describe what I found. The double-flange gel fit my ears the best, and I tried all of them. I also found a handy tip in the manual: The earpieces were more likely to stay in place if I ran the cables around the back of my neck and tightened them with the cable slider.

I haven't tried the X5 and X10 side by side, but Klipsch describes the X5 as having "a superior top end with more forward voicing," while the X10 "is for listeners who prefer a lot of bass in their music." At first blush the X5 did have remarkably little bass, even compared to other "lightweight headphones" within my frame of reference. It had a nice extended treble and a detailed midrange, but lacked lower midrange weight and anything that would evoke the thump of a rhythm section.

However, my feelings about this evolved even in the first few minutes that I spent listening to the X5 delivering an acoustic guitar. I kept turning the volume down. The reasons went beyond mere discomfort. That sent me for the iPod clickwheel the first time. But then I noticed that the communicative part of the midrange was communicating just as well at the lower volume. Would it keep on doing that with even less volume? Yes, repeatedly. By the time I found my comfort level, the X5 was barely whispering into my ear, yet I could could still hear the acoustic guitarist's fret buzzes. Later auditions with singing voices showed good intelligibility at equally low volume.

I decided to take the X5 for a walk in the park. This involved reseating the earpieces, and to my surprise, practice allowed me to achieve a better fit. This did not change the essential character of the X5 but did warm up the midrange a bit. Subjected to traffic noise, the gels did not seal as well as either a pair of full-size headphones or any noise-canceling product. But the X5's extremely clear mids and highs did not have to be turned any higher to compete. And after 20 minutes of walking, the earpieces were still firmly anchored in my ears.

I'd recommend trying this product before buying, if possible. But if you want the lightest possible accessory for your music player, the Klipsch X5 is a thoughtfully and well-engineered product that delivers on its promises. Though noise-cancellation models do better in the presence of internal combustion engines, the X5 is especially good for low-level (and therefore safe) listening in noisy outdoor locations.

Price: $250.

Mark Fleischmann is the author of the annually updated book Practical Home Theater and tastemaster of Happy Pig's Hot 100 New York Restaurants.