Racom Products Manufactures Telephone Line Surveillance Systems. One System Is Capable Of Simultaneously Monitoring Up To Six Target Telephone Lines. Providing Law Enforcement Agencies With Detailed Target Activity Information Plus The Minimized Audio. These Systems Are Turn Key Packages And Not Computor Based. Also, Two Types Of Minature "Field Remote" Monitors Are Available. They Work In Concert With The Base Product [Model 2816D] Enabling Covert Surveillance. Model Number: 2816D Base Unit LP2816D Dual Tone Extender DS2816D Dial-Up Extender