Remarks!!! 1)To support dual display, your pc's video card must be capable of supporting 2 out simutaneously. 2)to use the extended and spliced display function, your video card must be capable of doing so.As the dual monitor KVM Switch display only what was connected to the input.It is a bypass swicth and it can not processing those function by itself. 3)This is a KVM dual monitor switch, it is not a 4X2 KVM Matrix. 4)The dual monitor KVM Switch 4 port does not support keyboard hotkey control. Instead, it supports button and switch wire control. Dual Monitor KVM Switch 4 Port The KVM Switch 2 Monitors 4 Computers using only 1 set of keyboard, mouse and 2 monitors to control 2 computers, support display one computers main and extended desktop. ( For dual monitor setups, it requires every computer support 2 screen or above display functions and must support extended display). Dual Monitor KVM Switch 3 Modes The Dual Monitor KVM Switch 4 Port with 3 display modes. Mode 1: Two monitors splicing to display the picture of one host; Mode 2: Two monitors show the main screen and extended of one host; Mode 3: Two monitors respectively show the desktops of two host. 4K@60Hz Resolution The Dual Monitor KVM Switch 4 Port max resolution up to 4K@60Hz, compatible 3840x2160@30Hz, 1080P, 1080P 3D, 1080I, 720P, 576P, 576I, 480P, 480I. Dual Monitor 4 Port KVM Switch 4K@60Hz This Dual Monitor KVM Switch 4 Port help you control 4 PCs share 2 monitors (Extend display mode or copy display mode) by only one set of USB keyboard & mouse. Tips: hotkey switching is not supported Product Features: Support extended or duplicated display depending on computer setting. Support max up resolution 4K@60Hz, downward compatible Support controller or buttons switch USB devices that can be connected, such as: USB mouse, keyboard, U disk, printer, camera, etc. Built-in automatic equalization system, picture position, clear and stable Built-in ESD electrostatic protection circuit, all-round protection system safety Installation Step: 1. Turn off all devices and unplug all the cables; 2. Plug cables and USB cables into KVM switch and your computers/laptops ( cables not included): Please check the IN A1 & A2 & A3 & A4, IN B1 & B2 & B3 & B4 and USB IN1 & IN2 & IN3 & IN4 is corresponding, OUT A, OUT B is corresponding, NOT support mixed insertion. IN A1 + IN B1 + USB IN1=PC1 IN A2 + IN B2 + USB IN2=PC2 IN A3 + IN B3 + USB IN3=PC3 IN A4 + IN B4 + USB IN4=PC4 3. Plug mouse and keyboard into KVM switch; 4. Plug cables and USB cables into KVM switch and monitors; 5. Plug power supply into KVM switch; 6. Boot computers/laptops. Package List: Dual Monitor KVM Switchx1 USB Cables x4 USB Power Cord x1 Wired Switching Button x1 User Manual x1