Electrosound-Resistance-Substitution-Box-Electrosound-RESISTANCE-SUBSTITUTION-B-Resistance-substitution-box-1-to-999999R-range-6-decades-250V-power-source-0-5A-carry-current-150m A-at-250V-switching-current-600m W-power-rating-11cm-length-7-5cm-width-5cm-height-required-resistance-is-set-by-selecting-the-correct-value-from-six-rotary-decade-switches-which-clearly-indicate-the-value-selected-an-additional-1k-resistor-is-provided-connected-between-one-of-the-terminals-of-the-internal-r