What is the fine-grained topic of the following text: Panasonic KX-T7220 is part of the Panasonic KX-T7200 Series telephones that bring you the advanced features available with Panasonic's Digital Super Hybrid Telephone Systems as well as the ability to adapt to an expanding office environment. Only return the topic.
Panasonic KX-T7220 Telephone Features and Adaptability