Finally got my hands on the OBiEHS Electronic Hook Switch Kit and for those of you that don't know what an Electronic Hook Switch (EHS) is... It allows you to take a phone off hook without the need to life a receiver or press a button on the telephone, allowing you to answer inbound calls by tapping a button on your headset instead.
If you've ever purchased the OBiLINE adapter, you'll notice that the packaging is identical and that it doesn't come sealed. It's currently retailing at £29 (marked own from £59) here in the UK and is Eligible for FREE UK Delivery.
Expensive cable if you ask me but if you want to get your hands on one, click here