On the top of the headset is a dedicated On/Off switch and a charger jack. On the back of the headset is a bare earpiece, which you can then outfit with a slew of interchangeable earpiece covers. Joby provides two sets of three--the first set of earpiece covers consists of silicone tips that dip slightly into the ear canal to funnel the sound in, but are not meant to seal off extraneous noise. In fact, they look a lot like the eargel covers on the Bose TriPort In-Ear Headphones. The second set of earpiece covers has the more traditional earbud look and fit just inside the ear. (Do note that you'll have to install a small earpiece adapter in order to fit this style of earpiece cover onto the headset.) We found both to be really comfortable. We also really like that Joby provided us with different sizes of each style, to accommodate different-size ears.
There's also a space for an optional ear loop, but it's not on the headset itself. You'll have to attach a small magnetized disc on the back of the headset, and the disc has a slot for the ear loop. This may seem a bit cumbersome, but we actually like this configuration, as it allows us to place the ear loop wherever we want on the headset. That said--we found we didn't really need the ear loop most of the time. Of course, all earbuds and the ear loop can be configured to fit either ear.
We paired the Joby Zivio Boom with both the Apple iPhone 3G as well as the Sanyo Katana Eclipse. In a first test of the Zivio Boom's audio quality, we discovered a lot of static and buzz, and thus rated it poorly. Since then, we've learned that our unit was defective, and have received a new unit from Joby. The audio quality on the new unit is remarkably different. It turns out that the Zivio Boom's claim of noise-cancellation rings true. Callers heard us loud and clear, even when we were at busy traffic intersections. On our end, we heard them just fine, although we did still get the occasional static blip and their voices sounded a little tinny. That said, we found that we needed to extend the boom mic almost all the time to get that high-quality audio, which is fine, but it might be a little fussy for some people.
Features of the Zivio Boom include the typical capabilities to answer, end, and reject calls, as well as last number redial, voice dial support, three-way calling support, and the capability to transfer calls from the headset to the phone and vice versa. The Zivio Boom comes with a USB charging cable, an AC adapter, the aforementioned sets of three earpiece covers, two optional ear loops, and three more extra earbud covers.