This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics 202997-02, Ear cushion, Intended For Headset, Material Foam, Compatible With Poly EncorePro HW510, HW520.
The Plantronics 202997-02 Black Spare foam ear cushion is compatible with (No Suggestions) HW510, HW510V, HW520 and HW520V encorepro 500 series headset.