An allen wrench is really more of a variation on a screwdriver than a wrench. Also called a hex key, the allen wrench has a hexagonal end, and commonly sold as a hexagonal tube bent into an L shape, or as multiple straight hexagonal tubes affixed to a jack knife like housing, or as a set of screwdriver-like tools. Bits for use in electric screwdrivers and power drill attachments are also available.
Allen wrenches in a few key places in the DeLorean.. The rails that allow the seats to be slid forward and backward are held on with four M8 cap screws with allen heads, and the fuel metering adjustment screw on the fuel distributor uses an allen wrench.