Manufacturer: Ross Country of Manufacture: U.S.A. Type: Ross Precision Computer Number: Date of Manufacture: Scales: (Front) 24 circle precision scale + rule for approximate calculation. Scales: (Back) sin scale Number of Scales: 2 Gauge Points: Slide Rule made from: Metal (tin?) Cursor made from: Cursor Lines: Overall Length of Rule: 11.6 cm diameter Length of Scales: Width: Depth: 0.8 cm Weight: Acquired from: Alvaro Castro Date: January 2007 Condition: Poor Accessories: Leather sheath. Medium condition. Comments: Cursor missing from small rule.