The Leeds & Northrup Speedomax G Instrument's are manual test equipment manuals and books manufactured in the United States. 63 pages, Printed 12-1961 These instruments are produced by the reputable brand Leeds & Northrup, known for their high-quality products in the field of test, measurement, and inspection. The supplementary information provided with these instruments adds additional value to users seeking detailed instructions and specifications for precise measurements and inspections in various industrial and business settings.