The C-2000B now offers two operational modes for added flexibility. In the Single Line Ring Through Mode, the C-2000B allows single line phones to share a phone line with 1 to 4 entry phones. Tenants may con- verse with visitors and activate a contact closure to control gates or strikes. The C-2000B provides entry phone "Caller ID" and "Call Waiting Caller ID" and a "Call Waiting" tone when the phone lines is in use. Tenants may gain entry at each location by entering a keyless entry code. Add one to four entry phones to your standard home or office phones to provide: ? Door Communication ? Door Entry ? Gate Entry ? Keyless Entry