Incoming Call Block - Bundle Pack - 2 Items: Call Blocker/Caller Block Unit & Telephone Splitter Blocks up to 1,500 Numbers with a Push of a Button Line Powered - No Batteries Needed Ability to Block 800 #'s, Debt Collectors, Telemarketers...Or Anyone you don't want to talk to Large Lighted Caller Id Screen Bundle Pack includes Telephone Line Splitter