A hand held vacuum with a housing having a handle adapted to enable a user to manually adjust an angle of contact between the hand held vacuum and the surface being cleaned is provided. Using a housing equipped with at least a pair of mirrors in parallel relation to one another, a user can look down the barrel of his or her firearm. A digitally generated first spreading sequence is also generated at the first node. The time information item is read out in the event of a subsequent access to the assigned memory cell. Herein, the pad unit is constructed by a pad skin unit and a sensing unit. The housing may include a head for housing sensor electronics and a shield that encloses the head and is spaced from the head by an air gap.