This vintage Rockwell 18R is a 5-function arithmetic calculator circa 1975. Features 8-digit precision, algebraic logic and LED display typical of the era. Tested in working order. New battery included. Includes very good condition leatherette case, instruction booklet and original warranty card. Latch for holding battery cover in place is weak. Operates on 9V battery or 110 VAC adapter (not included).

Replacement "wall warts" are often available online. If you want to use a generic AC "wall wart", the specifications are 110 VAC input, 7.9 VDC 50ma output, plug type is mini-TR with tip positive.