Important : After connecting the computers and the monitors through KVM, you need to set the screen output mode on the computer (press Windows+P) and select the output mode in the pop-up window on the screen.We offer 12 months warranty. Tips 1: If you encounter problems when using the KVM connection, please contact us for after-sales support in time.Tips 2: hotkey switching is not supported. 2PC/3PC/4PC are all suitable: 4 ports does not mean that it can only be connected to 4 computers. You may have 4 computers currently, or you may only have 2 computers now, but you may need to use 3 or 4 computers in the future, then you can choose this switch. As long as your computer confirms that it supports dual-screen display, you can use 2 screens. 2 Switching Mode & LED Indicator: 1. Toggle selection on front panel; 2. Wired remote switch. Compatible with a variety of computer systems,such as Windows, Linux, Mac, Unix, Ubuntu, Raspberry and most other major OS; also supports HDMI devices without USB signal input like DVR, NVR etc. LED indicate the active computer. 3 USB 3.0 Ports: This dual monitor KVM HDMI switcher with 3 USB 3.0 ports which can recognize wired/wireless keyboard mouse, U-disk, printer or other USB devices.USB3.0 has a faster data transfer speed of up to 5Gbps, backward compatible with USB 2.0/1.1 devices while USB2.0 has a data transfer speed of 480Mbps. USB 3.0 KVM Switch Dual Monitor 4k 60hz: Our KVM supporting high resolution max up to 4K@60Hz, and also supports 3D and 1080P@60Hz or other lower resolution (Downward Compatible).supports separate audio and microphone output. Note: Only when both your computer Graphics card and monitor support 4K@60Hz then you can get 4K@60Hz effect, so if you want the max resolution you have to check your devices first. With Simulation EDID: This KVM dual monitor switch can simulate the EDID of the display, store the resolution and refresh rate of the display, it comes with EDID emulators in each input port, keep PCs always having correct display information. Without EDID, your windows may move around when switching. No longer have to sit and wait for the windows to adjust. Another feature of EDID is the ability to automatically identify the best resolution. USB 3.0 Dual Monitor KVM Switch HDMI 4 Port: This dual monitor KVM Switch is for you to control them using one set of keyboard, mouse and single or dual monitors to make your work space tidy and efficient, also a premium choice for working from home. Only when your computer supports dual display or multi display, you can use this KVM to achieve share 2 monitors. (Extended, mirrored or spliced display modes depend on your computer's graphics card).