The sonic screwdriver was a versatile tool and defensive "weapon" used by the Doctor. He used it primarily as a non-offensive tool to assist him during his adventures. The first version was a small, simple device similar to a penlight, used by the First and Second Doctor. It was also used by the Eighth after it was destroyed "Centuries Ago.' He explained how this occurred to his companion Samantha Jones: "It's a Time Lord tool. Time doesn't work the same way for Time Lord tools."