not have interchangeable headshells at all in an effort to reduce mass and improve rigidity, though at slight expense of user flexibility. Some cartridges were produced that mounted directly into the SME headshell mount of the arm (rather than into a headshell), notably from Ortofon. Series III The Series III was introduced in the late 1970s incorporating changes from the Series II models (which continued in production) covering both styling and its exceptionally thin and lightweight main tube, the entire arm being interchangeable rather than just the headshell. The Series III had very low effective mass to fit high compliance cartridges such as the Shure V15 IV. Although technically advanced, the Series III never achieved the market dominance of the Series II. Series V The Series V arm was developed as a medium mass arm more suited to emerging moving-coil cartridges with lower compliance than previously available moving magnet cartridges. The removable headshell was eliminated, and the horizontal knife bearing was replaced with ball bearings, both in order to provide a more rigid structure for the cartridge. In recent decades, as with many of their competitors, the company's products have tended to move further and further upmarket. Recent products include the SME V tonearm, and extremely expensive (and consequently relatively rare) decks. The company bucked their upmarket move with the M2 tonearm which sits at the bottom of their current range . Gallery See also List of phonograph manufacturers References External links SME homepage Phonograph manufacturers Technology companies established in 1946 English brands Audio equipment manufacturers of the United Kingdom