| Name and Model Number | Alvin Elite Vector No. 1157 |
| Country of Origin | Japan |
| Date of Manufacture | 1961 |
| Front Scales | Sr Sθ P' P [ Q CF CI C/LL1' ] D DF LL3 LL2 |
| Back Scales | Sh2 Sh1 A [ B K Th C ] D Tr1 Tr2 db |
| Scale Length | 25 cm |
| Type of Rule | Slide Rule |
| Construction | Celluloid on bamboo with plastic cursor |
| Area of Use | Electrical |
| Comment | Ricoh 157 variant. Differences between the Alvin 1157 and standard Ricoh 157 include scale extensions on A, B, C, and D scales, a wider multi-hairline cursor, and it is 25 mm longer to accommodate the scale extensions. |
| Rarity | RRR |
| Donor | Photo courtesy of Jodie Hobson |
| Match Number | 386 |
| 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. |