Like the HS810, the HS850 makes use of a body design that employs a folding microphone boom. The folding microphone boom acts as the on and off switch, as well as just providing a convenient way to make the headset smaller and more pocketable when not in use. When a call comes into your phone, you can turn on and answer the phone at the same time just by unfolding the microphone boom. You can end the call and turn it off by removing the headset and re-folding it. Using the headset in this way conserves battery power, since no battery juice is wasted on standby time - time where the headset sits around waiting to be contacted by a mobile phone or other compatible device. The physical design of the HS850 and the battery savings it imparts is my favorite aspect of the Motorola HS850.

Of course you don't have to remove and turn off the headset between calls. If the headset is already on when an inbound call comes, you will hear the ringing come through on the headset and can answer it by pressing on the main multi-function call control button. You can end the call with this same button, and adjust volume levels with the two volume buttons. If you are using a phone that supports the Hands Free Bluetooth profile, then you can also use the call control button to reject an inbound call or redial the last number.

The Motorola HS850 Bluetooth Headset's audio properties are also like those of the HS810 before it. The audio quality in both directions is very clear and understandable, but sounds a bit thin. You and the party on the other end of the call will both be able to understand each other easily, it just doesn't sound as full and natural as it might with some other headsets. The HS850 makes up for this small lacking by having great resistance to wind noise, though. That makes the headset perfect for people that enjoy driving with their windows down, or those that work outside. Most headsets are very susceptible to wind noise, the HS850 bucks that trend.

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