Protect USB devices against electrical noise, surges, and spikes. Isolates up to 4 kV - strong enough for hospital and medical use. USB 1.1 compliant. Includes 1-meter (3.3-ft.) USB cable. Just plug this tiny isolator in line between your PC and a USB device to provide protection from damaging electrical surges as well as insidious ground loops which can be especially disruptive in measurement applications.