| Name | Graphoplex 691 a Neperlog Hyperbolic |
| Front Scales | L P Ch A = B T<45ΓΈ ST S C = D Th Sh2 Sh1 |
| Back Scales | LL01 LL02 LL03 DF = CF CIF K CI C = D LL3 LL2 LL1 |
| Type of Rule | slide rule |
| Material | plastic |
| Dimension (mm) | 338x48.7x4.2 |
| Area of Use | generic |
| Origin of Rule | Herman van Herwijnen |
| Match Number | 1324 |
| Comment | |
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