Lanston Monotype’s copy of Futura. Drawn by Sol Hess in the Lanston Monotype drawing office between 1936 and 1947. The first weights were added to the Monotype typeface library in 1959. [Microsoft]
Letraset’s and Varityper’s Futura are at least partly based on Twentieth Century, see the Extra Bold. So is the digital Futura No 2.
Monotype’s digitization has 19 styles, incl. five italic and four (upright) condensed styles, as well as two Classified weights for small sizes and one all-caps Poster style. LTC Twentieth Century (Lanston Type Company/P22) was drawn by Colin Kahn and covers the Medium weight, with small caps and alternates.