Heallily Box Box Resistor Box Varistor Box Physical Tool Substitution Capacitor Package Include Characteristics Goods Description Substitution: the variable resistance box teaching instrument is suitable and wonderful for school, laboratory use. Resistor: decade resistance box, made of plastic material, flexibility and excellent durability, easy to use, for service life. Variable: a selection of professional variable resistance box, which has good stability and high accuracy. Traffic light: lightweight, easy and convenient to carry and store when not in use without any effort. Chakra button stones: it is used to measure the unknown resistance. it is used to measure the force and internal resistance of the power supply.