According to Plantronics, its Explorer 370 is a headset "tailored for the adventurer in all of us." A rugged Bluetooth model designed to meet the U.S. Army's MIL-STD 810 standard for survival in the field, the 370 is positioned at the top of the Explorer line and is water, shock, and dust resistant. This headset looks, feels, and sounds good and is almost indestructible.

The Explorer 370 certainly looks the part of a headset designed for rough play. Available in charcoal and dark blue, the entire unit is fully surrounded in a tough-feeling rubber, which also encases the two volume nubs on the top of the unit. Meanwhile, a rubber cover houses the charger jack. On the back, there's a rugged plastic hoop that's attached to a sturdy, reversible hinge. Despite all this extra reinforcement, the device is lightweight and comfortable to wear. I didn't feel weighed down even with it attached to my ear all day. It's a bit larger than Plantronics' usual midrange headsets, such as the Voyager 520, our current Editors' Choice; noticeably bigger than the svelte Plantronics Discovery 665; and about the same size as the Aliph Jawbone Bluetooth Headset.

A multifunction call button is recessed on the front panel. To the right of that is a multicolor LED indicator. Setting up the Explorer 370 is the same as with virtually all of the company's recent headsets: Set the phone to Discoverable mode, hold down the headset's call button until it blinks red and blue in an alternating pattern, and then enter in the usual Plantronics pass code of 0000. I paired the device with a Palm Centro, a Motorola Q, and a BlackBerry Pearl 8130 with no problems.

I have few complaints about call quality. The Explorer 370 had plenty of volume and sounded clear, if a little robotic, on a variety of test calls. It also exhibited decidedly more range than my trusty Plantronics Voyager 510, which begins to sputter whenever I walk more than 10 feet from my handset. One aspect I don't like is that when answering a call, the headset rings in the ear but doesn't beep again the way the Voyager 510 does to let you know that audio transmission has actually begun—it just takes some time to get used to this.

The Explorer 370 is an in-ear design, which may bother folks who don't like in-ear stereo earbuds. Unfortunately, it doesn't have the snug fit common to such models. In fact, I often found myself pressing the headset to my ear to hear the other party better. The Explorer 370 lacks noise-canceling circuitry, as well as the AudioIQ technology found on the Discovery 665. On the plus side, it's equipped with a windscreen that worked well enough to use while driving, at least with the windows rolled up. The Explorer 370 can be paired with only one handset at a time, unlike the Voyager 520, which lets you link to two.

So exactly how rugged is the Explorer 370? To find out, I left my review unit out all night in a parking lot in freezing temperatures and drizzling rain. Then a 4,300-pound Toyota 4Runner ran over it twice, which smashed it into the sharp gravel and dirt. It looked pretty sad and dirty, so I brought it home and ran it under the kitchen faucet for a while until it was clean again, making sure to get plenty of water inside the earpiece and microphone. You never know where dirt can hide. Then I dried it off and tried it on. At this point, the 370's front face was nicked pretty badly, the plastic part of the housing on the back had a crack that ran about three quarters of an inch across, and the formerly sturdy ear loop base had shifted, allowing it to flop a bit back and forth on my ear.

After these torture tests, the Explorer 370 lasted about an hour—pretty miraculous, when you think about it—before it permanently expired. A second review unit worked just fine, even after running it under lots of water. Moral of the story here is that as long as you don't subject it to extreme physical stress like running it over or, say, leaving it in a collapsing building, the Explorer 370 should be just fine. The headset is also a long-distance runner, lasting 7 hours 50 minutes on a talk-time rundown test—an excellent showing.

If my first Explorer 370 hadn't been pulverized by an SUV, it probably would have looked brand new for quite a while. Given the unit's size and mission, it's well built and stylish. And the Explorer 370 continues Plantronics' standing reputation for good-sounding headsets. In my view the Voyager 520 still wins on pure sound quality, while the Aliph Jawbone remains king in noise cancellation. But if you like your gadgets durable and rugged, the Explorer 370 should be near the top of your list.