| Name | Keuffel & Esser 4168 Doric Plastic Slide Rule with trig scales in degrees and minutes. Replaced 1068 |
| Front Scales | DF = CF CI C = D L |
| Back Scales | K A = B ST S = D T |
| Type of Rule | |
| Material | Engine Divided White Xylonite |
| Dimension (mm) | |
| Area of Use | |
| Origin of Rule | Michael O'Leary |
| Match Number | 4476 |
| Comment | |
| Thumbnail | No Picture |