Scientific, nautical, surveying, photographic, cinematographic, optical, weighing, measuring, signalling, checking, supervision, life-saving and teaching apparatus and instruments, namely, light-emitting diodes (LED); lighting ballasts; electric lightning conductors; electric light dimmers; electric light regulators in the nature of dimmers; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity, namely electric switches and elec...