PS/2 full key without PS/2 supports real full-key no punching. What does that mean? To put it simply, the system can recognize as many keys as you press on the keyboard at one time. For Usb keyboards, it is relatively lacking. Although some Usb keyboards also claim to have this function, they are generally made of signal simulation.PS/2 has lower latency The interface is different, and the working principle of the device is naturally different. usb works by polling the device.For example: What does your computer ask your mouse button for? The mouse button will respond by saying, move left. Similar to this question and answer . PS/2 sends interrupt requests through the system. The mouse button of the PS/2 will actively interrupt the current activity of the CPU, and then tell the computer what I want to do. Compared to the USB , PS/2 has lower latency, and the response time will be faster in actual use.Better PS/2 compatibility The current win7 system is still loved by many players. However, during the installation process of the win7 system, the USB driver is not integrated, which leads to the failure of the normal use of the USB mouse button. The PS/2 mouse button is not limited. Although some seem to be to use a USB mouse, the simulation effect is really mediocre, and a significant delay can be seen.Colour:blackMaterial:ABSSize: 6.7 x 3.2cmPackage Contents:1 x VGA ESP32 PSRAM moduleOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.