Scientific, research, navigation, surveying, photographic, cinematographic, audiovisual, optical, weighing, measuring, signalling, detecting, testing, inspecting, life-saving and teaching apparatus and instruments; automatic indicators of low pressure in vehicle tyres; petrol gauges; speed indicators; water level indicators; binoculars; microscopes; material testing instruments and machines; wearable speakers; microphones; smart speakers; headphones; loudspeakers; computer peripheral devices;...