The version varies between Nokia device models. To find it out for your device, visit your local Nokia website's support page, select your device and find "Bluetooth" in the technical specifications. If you don't find your device or its specifications in your local Nokia website, check Nokia Developer website or the user guide of your device.
To ensure interoperability between other devices supporting Bluetooth technology, use Nokia approved enhancements. Check with the manufacturers of other devices to determine their compatibility with your device.