PST Serial Response Box Driver: The PST Serial Response Box features a 0 millisecond debounce period. This is something that simply cannot be achieved from a standard keyboard! PST has engineered the PST Serial Response Box so that the response is time stamped and then the signal is verified for accuracy. A standard keyboard verifies the accuracy of the signal before the response is time stamped. The problem of variable debounce periods found on keyboards is solved with the PST Serial Response Box!Best of all, the PST Serial Response Box connects directly to the PC via the serial port! No additional hardware is required.