The Cisco Headset 320 Series isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Cisco Headset 520 Series isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Cisco Headset 530 Series isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Cisco Headset 560 Series isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Cisco Headset 720 Series isn't compatible with the Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Cisco Headset 730 isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Bang & Olufsen Cisco 950 isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.

The Bang & Olufsen Cisco 980 isn't compatible with the Cisco Small Business SPA300 Series or Cisco Small Business SPA500 Series IP Phones.