This is an Addimult Sumat-6 slide adder. The 6 refers to the number of digits that the calculator could handle. This is a very compact adder measuring 12.5 by 6 cm. As can be seen in the scans it is in extremely good condition and comes with the original stylus and a plastic cover and instruction sheet. The Addimult is very similar to the Addiator in design because the Addimult company was started by the son of the founder of the Addiator company. During WW2, Hans Kubler son of Carl Kubler took some of the dies and tools to Switzerland to set up an alternate Addiator factory, however, after the war Hans created the brand name Addimult and contiuned to manufacture slide adders in more or less friendly competition with his father (and his sister who eventually took over the Addiator firm). Addimult was rather successful but finally succumbed to the onslaught of inexpensive slide adders from Asia in the mid to late 60's.