This vintage hand-operated mechanical calculator was used for mathematical operations like multiplication, division, and roots before electronic calculators became common. Manufactured by the Sterling Plastics Company of Mountainside, New Jersey, likely between the 1960s and 1970s.
The device features multiple scales (A, B, C, CI, D, K, L, S, T) for various calculations and a clear plastic cursor.
It is marked "MADE IN U.S.A." and is ideal for collectors of scientific instruments I