The ZX74 Series of Decade Resistance Boxes are very high accuracy and stable six-dial instruments. There are 4 versions in the series with a maximum resistance of 1,111,111Ω. The ZX83 series adds another two Decade Boxes that extend the resistance range to 111,111,100Ω.

The resistive elements are non-inductively wound on high quality formers using a resistance wire of specially selected alloy. Each resistive element is heat treated and undergoes a controlled ageing process to produce the very highest stability and also a low temperature coefficient.

Switches are of the highest quality with low pressure contacts for long life and reliability. Each decade switch is manufactured using a fully enclosed construction for maintenance free operation. These decade boxes are housed in attractive robust metal cases with a retractable carrying handle.