This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Spare 40709-01, Compatible With Plantronics Blackwire 600 Series and Encore Series of headsets, Material Foam, Ear Cushion.
The Poly/Plantronics Foam Ear Cushion 40709-01 is specifically designed to suit Blackwire 600 Series ( Plantronics Blackwire C610 and Plantronics Blackwire C620) and Encore Series Headsets.