The Concise conversion tables and circular slide rule
Sama & Etami, Inc.
overall: 1/4 in x 3 1/2 in x 4 1/2 in
Pocket circular slide rule on a rectangular plastic card with "Thiokol Chemical Corporation" printed on it - likely an advertising give-away item. A plastic insert with useful constants and data fits into the side of the rectangular card. Comes in a blue plastic slip case and with instruction manual.