Spec Sheet Preview: The Alpha Communications® EPH2400-984RD Emergency Telephones are designed to be installed inside or outside, to a conventional POTS telephone line. The EPH2400-984RD Emergency Telephones can also be installed on a VoIP phone line, using the model# ABL-VOIP adapter. At the Security Desk or remotely called located, the EPH2400-984RD Emergency Telephones can be used in conjunction with our AlphaEntry™ software, when installed on a compatible Windows PC, and connected to a POTS telephone line.