AT&T - ATTEL50005 Accessory handset features an extra-large display with high-contrast black text to easily read your incoming Caller ID or call history records. Lighted handset keypad allows easy dialing in low-light conditions. Simulated full-duplex speakerphone increases participation by allowing both ends to speak and be heard for conversations that are more true to life. Eco-mode, power-conserving technology allows the system to use less energy to provide the best battery life. Call block directory allows you to save up to 20 names and numbers to stop unwanted calls from ringing through (Caller ID subscription required). Programmable design holds up to 50 names and associated phone numbers to quickly call and access your frequently dialed numbers. Handset also includes voicemail waiting indicator, last 10-number redial, mute, any key answer and more.