Notes: "This is a very small Aristo slide rule with scales only 10 cm long. The 816 is a single-sided slide rule with nothing at all on the back except for the date code, “3LS2”, which indicates it was made in the second manufacturing lot of 1973. There is nothing on the back of the slide or underneath the slide. The scale set is very simple, C, D, CF, DF, CI and A. There is also a 10 cm ruler on the upper edge. "
