Feature: 1. DUAL RJ11 PORT: The USB data modem utilizes dual RJ11 ports for connecting two fax phone lines or a telephone at the same time. 2. SUPPORT CALLER ID: USB data modem adopts for Conexant93010 main chip, support Caller ID, compatible with AT and extended AT command set. 3. EASY TO USE: USB 56K external modem is easy to use and supports stable fax sending and receiving. 4. SUPPORT OS: Computer laptop fax modem supports for Windows 98/2000/xp/vista, for WIN7, for WIN8 , for WIN10, for WIN11,32/64bit, for LINUX operating system. 5. ANTI THUNDER: Dual RJ11 Port USB fax modem is protected by fast anti thunder defend circuit to enhance thunder resistance. Specification: Item Type: USB 56K External Dial Up Fax Data Modem Material: ABS Main Chip: for Conexant 93010 Interface Type: USB Transmission Rate: 56Kbps Transmission Protocol: V.90/K56 Fax/Protocol: V.17, V.29, Group 3, Class 1 Main Functions: Unplugged Internet Access, Auto Send/Receive Faxes OS: for Windows 98/2000/xp/vista, for WIN 7 8 10 11 32/64bit, for LINUX Compatibility: Compatible with AT and Extended AT Command Set.. Package List: 1 x USB 56K External Dial Up Fax Data Modem1 x RJ11 Telephone Cable1 x Instruction Manual1 x CD ROM