| Name and Model Number | Keuffel & Esser DECILON 681130 |
| Country of Origin | USA |
| Date of Manufacture | Last patent 1961 – must have been mfg. in the 1960s |
| Front Scales | SQ1 Sq2 DF CF CIF L CI C D Ln0 Ln1 Ln2 Ln3 |
| Back Scales | LN-3 Ln-2 Ln-1 Ln-0 A B T SRT S C D DI K |
| Scale Length | 12 cm (5 in) |
| Type of Rule | Slide Rule |
| Construction | White plastic, adjustable aluminum end brackets – beautiful leather case |
| Area of Use | Generic |
| Comment | Beautiful well made top of the line K&E rule |
| Rarity | RR |
| Donor | Collection of Clay Castleberry |
| Match Number | 326 |
| Thumbnail (Click Picture for Details) |  |
| In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen |
| (1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD. |
| • RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| • RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale. |
| • RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale. |