I'M PLEASED TO OFFER THIS NICE DISCOUNTED CASH FLOW SLIDE RULE PUT OUT BY AMERICAN OIL COMPANY BACK IN 1962. IT IS 12 1/2" LONG AND 3" THICK. IN VERY NEW CONDITION AND COMES WITH ORIGINAL CASE. DO NOT KNOW MUCH ABOUT THIS BUT LOOKS IN EXCELLENT SHAPE. ANY QUESTIONS PLEASE ASK AND HAVE A FEW PICTURES TO DECIDE IF THIS ONE IS FOR YOU. SHIPPING PRIORITY ANYWHERE.

THANKS AND GOOD LUCK