| Name and Model Number | Pickett X-4 Executive |
| Country of Origin | USA |
| Date of Manufacture | ? |
| Front Scales | LL1, LL2, DF/m [ CF/m, TH, SH, Ln, L, CI, C ] D, LL3+.D/-.D, LL4+D./-D. |
| Back Scales | 31, 32, 3 , DF [ CF, CIF, T1, T2, ST, S Cos, CI, C ] D, DI, 1, 2 |
| Scale Length | 25 cm |
| Type of Rule | Slide Rule |
| Construction | Aluminum |
| Area of Use | Generic |
| Comment | Executive X-4 Vector Type Log Log - Dual Base Speed Rule.
Based on Pickett model N4. Made for Pickett executives. |
| Rarity | RRR |
| Donor | Collection of Clay Castleberry |
| Match Number | 241 |
| 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. |