The "EDR" portion of the spec means faster transmission speeds and lower power consumption. For exhaustive details about the Bluetooth versions, check out the .

Your paired Bluetooth phone and headset/speakerphone don't need to be in direct line of sight to function properly and maintain their connection. Depending on your product's range, however, you can't roam too far. You can determine what a product's operating range is by looking at its classification. (This is applicable primarily to headset users; for speakerphones, range won't be as much of an issue since you'll have to keep your phone in your car.)

Bluetooth Class 2: On this kind of headset or speakerphone, you're limited to a working range of up to roughly 33 feet (10 meters). Most headsets and speakerphones today belong in this group.

Bluetooth Class 1: Headsets that meet this spec offer a range of up to 328 feet (100 meters). Models supporting this range are far less common. Only one headset we've seen, the , is categorized as Class 1.