1. This is a duplex circular rule. More information is given for the Gilson Midget. Scales which are present on this rule but not on the Midget are shown in italics. The scales on the front face (using where applicable standard nomenclature) are:

• C, as the rule has two cursors, no D scale is needed.
• CI, a reciprocal scale.
• A, squares with normal decimal markings.
• K, scale of cubes
• L, logarithms (base 10)
• L3, log-log scales from 4 to 4000
• L2, log-log scales from 1.15 to 4
• L1, log-log scales from 1.0145 to 1.15
• L0, log-log scales from 1.0015 to 1.0145. The log-log scales are shown highlighted below.
• A, with with binary fractions, that is, against 1.5 on the A scale the number 1 1/2 is marked on the Ab scale
• Fractions, in 1/64ths . With two cursors it is possible to added fractional numbers.
• Drill and Thread Scales . The scale from 60 to 1 and on through A to Z   is for drill sizes. To find the size of a numbered or lettered drill you put the cursor over the number or letter and read the size as a decimal on L or as a fraction on the fraction scale. To find the size of drill to use for tapping a perfectly full thread use the Thread Scale. Set the long cursor at 5 on the Log Scale and the short cursor at the number of threads on the Thread Scale (either USS or V form). Turn the long cursor until the short cursor is at the bolt size on the Fraction Scale and the long cursor will give the drill size on the Log, Fraction or Drill Scale, as desired. (Thanks to Bill Kale for the explanation).
• Millimetre to inch conversion .

2, On the rear it has three scales each for sin and tan covering the ranges 0° - 30° : 30°- 60° : 60° - 90°. (detail back view). It also repeats the fraction scale.

3. The rule has two cursors on the front face, this is an alternative to have two rotating disks as on the Concise and Circulator rules.