Panasonic KXTGDA20N dect_6.0 2-Handset 2-Line Landline Telephone Additional Digital Cordless Handset compatible with Digital Cordless Phone Series KX-TGC21, KX-TGC22, KX-TGD21, & KX-TGD22 Sleek Design Energy-Star Certified Accessory Handset does not work alone