"Locke Adders" were a form of an abacus (but looking way fancier) made by Clarence E. Locke, patented in 1901. It was as pretty as its utility was limited, but is an interesting item for people collecting early adding machines. This one I estimate was manufactured around 1906.

It is made of very lightweight stamped aluminum, measures 10 3/4" x 4" x 1/2" and weighs a couple of ounces. Was marketed as "pocket sized" but I don't know anyone with pockets this deep. 

Is functional, as intended, but as I said it was not a great tool to begin with, it does not perform ten carries, they have to be done manually and reading out the result requires an awkward angle.

For cosmetic condition, see the pictures. It is an extremely rare collectible, though, not many survived to this day.