Slide rules HOME page COLLECTION CIRCULAR RULES 
Make Concise, Japan
Model No 28N
Notes

1. This rule appears to have been given away by Time Life. It came in a plastic pouch and with documentation both of which mention Time Life.
2. A copy of the instructions can be found here.

Front view
0c01-concise28-01.jpg (18857 bytes)
Detail - front view
0c01-concise28-02.jpg (36069 bytes)
Detail - back view
0c01-concise28-03.jpg (24096 bytes)
Manufacturing date 1960+
Length Circular
Material Plastic
Scales D, C, CI, A,  K
Gauge points p: A,B:
C: C,D
Cursor Plastic
Hair lines  
Documentation Complete
Condition Very good, include plastic case