| Name and Model Number | Dempster Rotarule AA |
| Country of Origin | U.S.A. |
| Date of Manufacture | 1972 |
| Front Scales | K, A, D [C, CI, CIF, S, C, ST, T, CT, G (2 scales), B, F/i] |
| Back Scales | L, LL%, LL1, LL2, LL3, C [V1, V2, DLL, D] |
| Scale Length | 13.0 cm diameter |
| Type of Rule | Disc |
| Construction | Plastic |
| Area of Use | Generic |
| Comment | |
| Rarity | RR |
| Donor | Collection of Rod Lovett |
| Match Number | 18 |
| Thumbnail |  |
| RR | = Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| RRR | = Very rare -- only very few known to collectors; may take several years before one comes up for sale. |
| RRRR | = Extremely rare -- a museum piece; unlikely that an example will ever come up for sale. |