1. This rule was made especially for electronic engineers; which is rather ironic as it was advances in electronic engineering which led to the demise of the slide rule.
2. The front of the rule has "standard" scales as found on many slide rules.
3. The back of the rule has two types of scales. Firstly it has set of scales covering several logarithmic cycles of frequency, resistance, impedance and inductance. For example in the case of resistance these go from 0.01 ohms to 100 M Ohms. With these scales it is possible to perform electronic calculations to 2 significant figures but also to get the exact order of magnitude (e.g. be sure, for example, that an answer is 260 rather than 26 or 2600). Then using the A, B, CI, C and D scales (also on the back) together with special gauge points get the answer to 3 significant figures (e.g. 261 rather 260 or 262).
4. For a description of how to use this, and other electronic rules, click here.

Front view

Front left

Front right

Back view

Back left

Back right