Lissabon,

ML20

Nr. M-801

Screenshot from promotional video by Metropolitano de Lisboa showing the first new metro train inside Stadler factory.
Trains will consist of 3 nondetachable carriages with passengers being able to freely move between the three carriages (just like it is with the ML97 and ML99 series).

Source — https://fb.watch/sgryX0_OUm/