This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Spareheadband 72742-02, Supportwh300/wh350 Cs510/520 (72742-02), Black.
The Plantronics Spare Headband Support 72742-02 for WH300/WH350/CS510/CS520 is a replacement headband support for the Plantronics WH300, WH350, CS510, and CS520 headset.