A five decade capacitance box to compliment the RM6N range of resistance decades. Styled in the same ergonomic desk type case, the CM5N is a useful addition to any laboratory, as well as for industrial and educational use. The required capacitance is set by means of rotary switches with skirted knobs and stators giving a clear indication of the dial setting. The capacitors are a combination of polycarbonate and polystyrene, generously rated minimum 160 V d.c. with a good dissipation factor and high insulation. A useful feature of this unit is the residual capacitance being compensated for on the 10 x 100pF and 10 x 1nF dials so that the actual value of the dial setting appears at the terminals.