This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Spare Neckband Hw540 88815-01, Black, Compatible with HW530, HW540, Replacement neckband, Flexible and lightweight design.
The Poly/Plantronics Spare Neckband HW540 88815-01 is a replacement neckband which is specifically designed to suit EncorePro HW530/HW540 headset.