Home Phone Call Blocker System - Caller ID Screener Box Device Machine That Blocks Caller Number, Robocall, Telemarketer, Spam Calls on Landline Telephone w/ Digital LCD Display Screen - Pyle PCLBLK52 INSTANT SCREENING: Pyles Home Phone Caller ID identifies and displays telephone numbers of incoming calls. Instantly screens incoming calls allowing you to easily add caller numbers to the whitelist/blacklist, save incoming/outgoing caller numbers UP TO 1500 CONTACTS: The landline blocker system is FSK/DTMF compatible allowing you to whitelist up to 1500 contacts, blacklist up to 1500 contacts, incoming call up to 100 contacts, outgoing call up to 50 contacts or block up to 20 area codes EASY INSTALLATION: Features hassle-free plug-in installation. Just connect your phone line to the LINE port coming from wall or your phone service provider and then use small cord to connect PHONE port or socket directly to the actual phone set BATTERY OPERATED: This incoming call blocker device is powered by your phone line but uses 3 AAA batteries as backup (not included). To install or replace the batteries, open the battery cover located in the back of the unit and insert the batteries DIGITAL LCD DISPLAY: Equipped w/ digital LCD display w/ backlight function and 5 level brightness adjustment. Features flashing LED light for incoming calls, and simple button controls for setting date, accept/whitelist, reject/blacklist, delete, etc