The pcProx® Sonar USB Presence Detector from RFIDeas is a plug-and-play presence detector. It is not a card reader.
The pcProx Sonar resolves security risks and privacy concerns on unattended computers without any additional software or user action. As soon as a user leaves the computer, the detector automatically locks the computer. In turn, it detects the presence of a user so that the computer is not locked during use until the user physically distances himself.
The sonar can be easily connected via a USB port to the PC and emulates a keyboard device.