CablesOnline, 1ft 3.5mm Jack to RJ9/RJ10 iPhone Headset to Cisco Office Phone Adapter Cable, IP-CS01 (1) 3.5mm TRRS female jack 4P4C male plug Use your existing iPhone/ iPad, or similar TRRS headset with your Cisco-based phone Avoid having to purchase an expensive Cisco headset Eliminates the need to have more than one headset