Batteries, electric; Computer mice; Computer peripherals; Computer switches; Converters; Data processing apparatus; Downloadable computer programs for use in teaching children to read; Downloadable educational course materials in the field of English, Math, and Science; Earphones and headphones; Electric cables; Electric cables and wires; Electric connections and connectors; Eye glasses; Gasometers; Goggles for sports; Gravity measuring instruments; Height measuring instruments; Instruments f...