MCHEETA Call Blocker,Smart White List Landline Phone Blocker, Block All Robo Calls, Block All Spam Calls, Telemarketing Calls, Sales Calls Automatically Block robo calls automatically This blocker can blcok 100% robo calls and 99% telemarketing calls, don't need to press reject buttton. White list function All incoming calls will save in white list autamatically, excellent technology to save numbers and block numbers. Block unknown numbers This item will block all numbers without caller id.It will analyzes the numbers before signal pass to our call blocker. Easy installation very easy to install and use, elderly know how to use it with the guide of manual. Extra power choice This products support battery and line power, with chip memory function, data won't lose even power off.