As the 'BT' name suggests, the ATH-SR5BT comes with the ability to connect your headphones via Bluetooth 4.1. It also comes with aptX technology which allows for greater data transfer, enabling better audio quality via the wireless / Bluetooth technology.
The headphones have a 10m (line of site) distance from its data source, however we would normally consider that to be around 5m inside with walls and the likes of getting in the way.
In addition to the wireless functionality, it also has a headphone jack for wired use. This is great if on an aeroplane (where wireless is sometimes banned) or in case the battery runs out. On that note, the SR5BT boasts a massive 38 hours play time and 1,000 hours on standby. Charging only takes 5 hours but can still be used via wired if battery is low. This should allow for massive listening sessions between charging.
On the left headphone you will notice the NFC logo. This enables you to pair the headphones with other NFC compatible devices just by touching the headphones on the sound source device. This makes pairing that much easier. It also makes it much easier to change the device you wish to receive the source from too.