This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Savi Spare Headset And Charging Cradle 211423-03, Black, Wireless, Supra-aural, Over-the-head.
The Poly/Plantronics Spare Headset and Charging Cradle 211423-03 is a replacement part and accessory which is specifically designed to fit and work accurately with W8210 (And -M).