On the back of the headset is an earpiece that rests just inside the ear without protruding too deeply in the canal. This resulted in a really comfortable yet secure fit. There's also an adjustable ear hook that you can switch to wear on either the right or the left ear. The hook itself is extremely flexible, and it's bendable for a more comfortable fit. We managed to wear our headset for a few hours without noticing any discomfort.
We tested the headset with the LG VX5300 and the T-Mobile Sidekick 3. It paired with both devices successfully, and we answered and ended calls without a hitch. Call quality was loud and clear, although it did suffer a little in noisier environments, with callers insisting that we speak up. The features on the headset are pretty basic: you can answer, end, make, and reject calls; dial by voice, redial the last number, and place a call on hold. It also supports Bluetooth 2.0.
The Jabra BT125 has a rated talk time of 8 hours and a rated standby time of 7 days.