For absolute secure phone conversations, The Miser utilizes multiple unique encryption algorithms with 1 million user programmable codes to secure voice communication links and provide maximum security. The Miser provides privacy for confidential conversations even if a line is electronically tapped. Eavesdroppers will not be able to decipher the contents of the communication link. The Miser can secure multiple links for conference calling. A maximum of ten (10) links may be secured simultaneously. Connects between handset and your phone base. Note: A minimum of (2) units is required for operation. Specifications: Intelligent Microprocessor Control -- 1,000,000 random codes. Fits almost all telephone sets ( home ordinary phones, office PABX / KTS phones ). User programmable access codes from phone keypad. Multiple unique encryption algorithms used when securing link. Multiple link encryption for conference calling. Dual LED and Audio tone status indicators. Self contained power- up diagnostics. Easy to install and maintain. Optional 9V Battery for portability. Model - TS-M