4-port PS/2 KVM switch LED display Plug and Play. KVM Switch 4 Port is compact size design, easily portable. Support Microsoft. Intellimouse, Logitech Net Mouse, etc… Support DOS, Win 3.X, Win95/98/SE/2000/ME/XP, WinNT, Vista, Netware, UNIX, Linux. Hot Plug-add or remove connected PCs for maintenance without powering down the KVM switch or PCs. High Video quality. NO software required - easy PC selection via Push buttons, Hot keys. Auto scan mode for monitoring PCs. LED display for easy status monitoring. Buzzer sound for switching power confirmation. Operational 9V 500mA power adapter