Elenco Resistor Substitution Box Soldering Kit with Iron and Solder Hone your DIY soldering techniques on the Resistor Substitution Box Soldering Kit Enjoy the pleasure of having assembled and soldered it yourself Values selected for your resistance substitution box were determined to be the most commonly used in modern solid-state circuits Values are from 10 to 1,000k (1 meg) in 24 steps All resistors are 5% tolerance 1/2 watt Includes: PCB, electronic components, instruction & 25 watt soldering iron, stand and lead free, rosin core solder PCB measures 611mmX1016mmX16mm Add this kit to your STEM curriculum From the company that brings you Snap Circuits - 9 volt battery not included