Vintage Ohmite Ohm's Law Parallel Resistance Calculator Ruler w/ Case

Vintage Ohmite Parallel Resistance Calculator and Ohm's Law Slide Rule, made in Skokie, Illinois. Includes original mailing envelope addressed to San Francisco. Collectible tool for engineers and electronics hobbyists. Light wear consistent with age, overall great shape. **Vintage Ohmite Parallel Resistance Calculator & Ohm's Law Slide Rule **Includes original envelope (stamped & addressed) **Manufactured by Ohmite Manufacturing Co., Skokie, Illinois, USA **Dual-sided design: resistance calculator on front, Ohm's Law calculator on back **Rare collectible piece of engineering history **Condition: Excellent vintage condition; minor age wear, envelope shows expected discoloration and handling marks