Astronomical spectrographs; Batteries; Breathing apparatus for underwater swimming; Burglar alarms; Directional compasses; Divers masks; Diving gloves; Diving suits; Goggles for sports; Infrared detectors; Life buoys; Life jackets; Odometers; Optical inspection apparatus; Protective helmets for sports; Range finders for cameras; Signal processors; Solar panels for the production of electricity; Telescopes; Wearable activity trackers