From Wiki

Lightning Adder

• Type: Adding Machine
• Size: 12 Inches / 30 cm
• Material: Steel

Used mainly for quick addition of long columns of figures. Subtraction is possible, but you have to figure out for yourself what hole to use. You want a really heavy-duty stylus, something metal. This thing will chew plastic right up. A handle at the left end clears the accumulator. Felt-lined base.

Produced by The Lightning Adding Machine Co. Inc. of Los Angeles, Calif. U.S.A.