Promate HDMI Switch 4K Splitter, Premium Ultra HD 4K 60Gz Bi-Directional HDMI Switch with 7.5Ghz Bandwidth Speed, Aluminium Crafted Casing, and Built-In Manual Switching Control for HDTV, Switch-HDMI

Bought this in a hurry thinking I will be able to connect two additional monitors simultaneously to my computer after reading that it is a "splitter". Turns out it will connect two computers to one additional monitor and the button is designed to switch between which computer screen you want to be mirrored on the additional monitor. Overall a solid high-quality product and works perfectly if you want two computers connected to one monitor.