The Panasonic KX-TG6845B DECT 6.0 Plus Expandable Digital Cordless Answering System with base keypad includes 5 handsets. This answering system boasts an Enhanced Noise Reduction feature that suppresses background noise around the caller while simultaneously enhancing their voice so it's easier to hear them if they're calling from a noisy location. A powerful battery back-up system keeps you connected even when the power goes out. Keep a charged handset in the base unit and you can still make and receive calls with the other cordless handsets. To maximize clarity or accommodate hearing loss a Tone Equalizer control feature actually 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. By increasing the frequency of error correction up to 80x the transmission quality is improved and the phone's range is extended.