Plantronics A10 Cord (P/N 66268-01, formerly P/N 33669-01) is a special cord (QD - Modular) which allows for an H-series headset to be adapted to headset-ready phones which would normally take a P-series Polaris headset. The typical application for these cords is a call center or office already equipped with H-series headsets, and a new Polaris-compatible phone system is purchased. By buying these cords, you can keep your existing headsets rather than having to buy new Polaris-versions. Due to the specialized nature of this particular cord, please contact us to determine if this is the correct cord for you to be certain before ordering. There are several different cords which look the same so if you have any doubts about the part number you need, please call us and provide your telephone brand name and model number for personalized advice.