| Name | Blundell Radiac Pat. No. 644944 |
| Front Scales | = A1 A2 = B1 B2 = C1 C2 = D |
| Back Scales | = F1 F2 = = E1 E2 = |
| Type of Rule | slide rule |
| Material | PVC |
| Dimension (mm) | 300x66.5x9 |
| Area of Use | log/tech |
| Origin of Rule | Herman van Herwijnen |
| Match Number | 504 |
| Comment | |
| Thumbnail |  |