Each value corresponds to a separate inductor, no series or in parallel. Inductors' Tolerance +/-10%, With 4mm banana sockets, easy to connect wires. Programmable Inductance: 1uH to 2.2mH, E12 standard total 40 values. This is "inductance substitution box" good low-cost alternative solution, can flexibly and quickly set inductance range from 1uH to 2.2mH, E12 standard total 40 values. for educational experiments, electronic engineering design or test trimming are excellent applications. Colour: Material:PCB+electronic components The factory batches have different silk screen numbers, which does not affect the use Package Contents: 1 x Programmable Inductor Board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.