Additional cordless handset accessory compatible with the following series of Panasonic Digital Cordless Telephones: KX-TGM430B* - NOT a standalone product. Hear and be heard, loud and clear with Volume Boost control for amplified caller voice volume up to 40 dB, includes six voice Tone Settings and a loud base unit Ringer. A powerful battery back-up system keeps you connected even when the power goes out. To maximize clarity or accommodate hearing loss a Tone Equalizer control feature lets you adjust bass, mid-range or treble tones in a caller's voice for maximum clarity. The DECT 6.0 PLUS takes the superb sound quality and outstanding range of DECT 6.0 phones to a whole new level. Includes Power Backup, Speakerphone, Talking Caller ID, Talking Keypad and Phonebook, 9 Speed Dials, 250-number Call Block, Intercom, Accessories, and Cordless Phone System is expandable up to 6 handsets.DISCLAIMER: *The corresponding models are subject to change without notice. You must register this cordless handset with your phone's base unit before it can be used. DECT 6. 0 is a North American marketing term for DECT devices manufactured for the United States and Canada operating at 1. 9 GHz.