This KVM switch is very well built and works as described. I have a 4K monitor, Mac Mini, Intel NUC, Logitech unifying receiver and a USB amp/dac. Everything works (nearly) and switching from Mac to NUC takes just 3-4 seconds. The unit was supplied with a UK power adaptor/plug and good quality HDMI/USB cables. There are 4 choices of input switching: Mouse gesture, Hot keys, Remote and the button on the front panel.The good news is:No problems with audio or video quality, full HDMI support (4K@60Hz, HDR, HDCP etc)Hot key switching can be Scroll Lock + Scroll Lock + 1 (or 2 , or page up/down) OR the right CTRL key e.g. CTRL + CTRL + 1 etcLogitech K780 keyboard and M720 mouse work seamlessly with the unifying receiver plugged into this unit *The unit is silent and barely gets warm in useThe not so good news:* If you plug the unifying receiver into the mouse or keyboard port you cannot use Logitech Options as the receiver will not be found. It all works as a standard keyboard, mouse with scrolling and hot key switching. If you plug the unifying receiver into the accessory USB port then Logitech Options will work fine, but you loose the hot key switching capability. I use the former option as I don't really use options software and I want a USB amp/dac plugged into the accessory port. The USB amp/dac works seamlessly and has had the added benefit of eliminating the NUC's audio interference.I don't have a keyboard with a scroll lock key so the option to change this to the right control key is welcome. However, would you believe it, you need a keyboard with a scroll lock key to change the setting! You can't use on screen keyboards to do this either. I borrowed a keyboard for this one-off event....and being really picky, the front panel LEDs are too bright and the function beep (which can be turned off) is just too loud.If this sounds a bit negative it isn't meant to be because I doubt you will find better at double the price. It does what I want and I'm keeping it.*UPDATE* Following communication from TESmart UK I can confirm that:if you don't have the key, you can change the hotkey switching mode by pressing the "Select" key on the switcher panel until you hear a continuous beep, then switch the unit off and back on.