Students love to do unknown experiments. This resistance board is conveniently wired so every student can have his or her own unknown resistance. You can quickly assign a unique number combination for each student. There are more than enough combinations for everyone in your class. This set of nine precision resistors is ideal for use with a wheatstone bridge or other resistance measuring experiments. The resistors are mounted on a PC board with a binding post at the end of each resistor (nine on the periphery, one at the center). This layout allows any two resistors to be wired in series. The values of the resistors are unknown to students but are provided in the included Teacher's Instructions. This board is irresistible!