Data processing apparatus; Global Positioning System apparatus; audio- and video-receivers; audiovisual teaching apparatus, namely, overhead projectors, film projectors; audio interfaces; computer memory devices; measuring apparatus, namely, graduated rulers; electric measuring devices, namely, laser distance meters; measures, namely, compasses, slide rules, tape measures; current rectifiers; video screens; camcorders; fibre optic cables; virtual reality headsets; dictating machines; blank ma...