This was pretty much what I needed to do a monitor, keyboard and mouse share. Interestingly, when I use my LG television remote power on/off, it causes this switch to change inputs :)

It works fine switching video, keyboard and audio which is why I bought it. If you accidentally move the mouse to the right it will switch computers. Monoprice calls this a feature and there is no software switch to disable the feature. Happens most when you back up a web page then it switches because you moved the mouse to the right of the screen.

I purchased the 2 input switch. Everything works but PC2 audio plays when PC 1 is selected and visa versa. Not a deal breaker. Easily remedied by swapping the audio input cables but worth noting.

This switch does not support the modes that are advertised...or really any video modes. There is constant tearing and re-syncing on the video. I have tried multiple PCs running different Operating Systems all which work directly to the TV do not work through this switch.

I tried buying Monoprice 4k certified HDMI cables and it still doesn't work.

If you are a fan of your screen constantly flickering on and off, this is the product for you. Otherwise...hard pass.

So, I'm using this Blackbird 2x1 4K KVM switch to switch between an ASUS Z87-Plus mother board (Intel i7-4770K) and a Mac Studio M1 Ultra. The KVM is attached to a MS Wireless Keyboard 800 / Mouse 1000 and an ACER V276H monitor. The KVM works well - but has a few issues that I've found workarounds for:

1) My LG OLEDxxC1 remote off button was triggering a computer switch. I covered the KVM remote sensor and remote sensor jack with electrical tape - FIXED.

2) Switching to the Mac Studio, infrequently doesn't sync up and I get static. Need to switch over and back. Possibly not the fault of the switch - could be Mac or monitor. OK workaround

3) The mouse traverse switch function is a problem.
This function causes a computer switch to trigger if you move the cursor up and down while positioned off monitor to the right side. Windows at full screen size typically have a slider on the right side - and using the slider by holding the left mouse button and scrolling slowly triggers an undesired computer switch Sometimes this happens even when the windows is not even all the way on the right side. If you have multiple displays (on one computer), the function also prevents the OS from seeing the mouse move off screen which breaks the ability to move the cursor between screens or to push a window between the screens.
Unfortunately, there is no keyboard control sequence on the KVM to disable this function, which would have fixed this issue without additional effort. The KVM is designed so that the front USB ports do not support keyboard or mouse triggered switching and the rear USB ports do support keyboard or mouse triggered switching.

There are a few possible workarounds to turn off the mouse transverse function:

a) If your mouse and keyboard have separate dongles, put the mouse dongle in a front USB port and the keyboard dongle in a rear USB port.

b) If your mouse/keyboard has a single dongle, you can put the dongle in a front USB port, but this disables the ability to use the keyboard control sequences to affect a switch between computers.

c) If your mouse/keyboard has a single dongle and you don't have multiple displays, you can put the dongle in a rear USB port and avoid putting your windows at full size or having the sliders near the right side - and if you happen to trigger a switch you don't want, just switch back.

d) In my case, I had a mouse/keyboard with a single dongle, I have multiple displays on both computers, and I exclusively want to use the keyboard to trigger a computer switch. I solved this issue by purchasing a second MS Wireless Keyboard 850/Mouse 1000 with a single dongle (found it online for $25). I use my old keyboard/dongle in the rear USB and my new mouse/dongle in the front USB.

So, for $89, this KVM was not usable for my case, and I would give it maybe 1 star. (Perhaps 4 stars if you don't have multiple displays).
For $114 ($89+$25 for a 2nd keyboard/mouse), it is a very good switch and I have given it 5 stars.

Purchase the 4x1 switch on Amazon (in stock there), so here is the review I left:

Wanted this switch to access two Dell PC towers and a Mac Mini using one keyboard, mouse, and set of speakers. This product does this admirably. The case it metal, the LEDs are bright, the buttons are responsive (mechanical, though it also comes with the remote control to select the input), comes with premium USB-3 cables (A to B male connectors), as well as a power adapter with a screw-in connection to the switch.

So, while I'm delighted with the switch, there are two caveats - one, occasionally it takes a minute or two for the PC/Mac desktop to appear on the monitor and two, the switch needs to be on before turning on the PC (I turn off the switch after I'm done using the PCs).

All in all, a great switch is you need to access 4 PCs - highly recommended

pros: This device feels solid with nice tight connections, works as advertised. Isn't flaky like a lot of KVMs.

cons:

1. you are paying for an optional IR switch that you arent going to use. the device is usually two feet from your keyboard sitting on your desk. Why do you need a remote control for something two feet away? Lower the price the drop the IR switch.

2. "Mouse Traverse" is an anti-feature. The KVM has this feature where if you move the mouse off the right side of the screen and leave it there for a few seconds it switches computers. This mostly happens by accident. It is really bad if you don't know about the feature.

My Blackbird 2XHDMI KVM Switch is an asset to my home office with a Desktop computer and a Notebook computer linked via HDMI ports. The mouse function sometimes fails to transfer, so I must cycle between the Desktop and the Notebook computer to reacquire moiuse function on the Desktop, which is my primary computer.

For some reason, if I boot into my linux (ubuntu) partition, the mouse/keyboard are only recognized if plugged into the front USB ports. I'm not sure if the rears are recognized under linux at all, but it makes for a more cluttered desk than I was hoping for.

The same computer works fine w/kb/mouse plugged into the rear USB ports if I boot into windows.

This product is well made and looks and feels good. Once I set it up, this worked great with one computer but not the game computer. I spent 4 plus hours changing the Nvidia console to get it to recognize this switch but was unsuccessful. The game computer which has a GeForce GTX 980Ti graphics card works great on the monitor without the KVM switch. Even an IT professional was completely unsuccessful at getting this KVM to work.