Blåtandshandsfree 3.0 till mobil med Bluetooth-version 2.1?

De brukar vara bakåtkompatibla så det bör funka.

Citat: Backwards compatibility

Bluetooth 3.0 is backwards-compatible. This means you can keep all of your current Bluetooth-enabled devices. This backward compatibility is enabled via a 2.4 GHz Bluetooth radio in addition to the Bluetooth 3.0 radio chip. However, note that transfer speeds are only as fast as the slowest device, which means that if your Bluetooth 3.0 device is connected to a Bluetooth 2.1 device, your transfer rate will be limited to 2.1 mbps.