It has many names, in different countries and different languages it is often called the Skeleton type, Skeletal and Skelettapparat in German. People nowadays also call it the Eiffel tower, although this used to be the nickname of another telephone, not an Ericsson model. It drives some purist nuts, when they here this telephone called after the famous Parisian landmark.
This model was introduced in 1892 and remained in production until the early 1930s and personally designed by Lars Magnus Ericsson. It was developed from an earlier model, the AC100 that shared the same distinctive base, with the curved metal frame. It had a separate receiver and transmitter, the latter mounted on a horizontal tube, that could swing 360 degrees.
This version , the AC110, was the first Ericsson telephone that had an integrated handset, Ericsson being responsible for the widespread use of that, although they did not invent it themselves. It was produced by many other manufacturers, under licence, often with local variations on its design. The curved metal pieces that form the base of this telephone are actually also the magnets for the generator.
This model is so iconic that it was pictured in the Ericsson company logo for many decades.
Although this model is painted plain black, it often has a decals with a flowery pattern on its base. In this case many of its parts are still nickel plated, where many other examples have been brassed out.