StarTech ICUSB2324X 4 Port Professional USB to Serial Adapter Hub with COM Retention Changer Type: USB to DB9 (RS-232) Specifications: Connector Types 4 - DB9 Male Connector Types 1 - USB A Female Compatibility Supports: USB 1.1 and above Maximum Data Transfer Rate: 230 Kbps OS Support: Windows 2000, XP, Server 2000 and 2003. Limited functionality with Windows NT 4 and Vista. Weight: 1.42