An extraction unit (10) for extracting cartridges (1a; 1b) of two different dimensions (da, ha; db, hb) comprises a seat (14,20) for receiving any of these cartridges (1a; 1b) for extraction thereof in the seat. The seat is delimited by a first part (20, 30, 33) and second part (12,13,14) that are relatively movable between a cartridge extraction position and a cartridge loading and/or ejection position. The first delimiting part has a first member (30) and a second member (33) that are relatively movable between: —a first member position delimiting a cartridge cavity of a first depth (Ha) for receiving a cartridge (1a) having a first height (ha); and —a second member position in which the ca cartridge cavity has a second depth (Hb) different to the first depth (Ha) for receiving a cartridge (1b) having a second height (hb) different to the first height (ha). The unit (10) further comprises an actuator (21,25), in particular a motorized actuator having a motor (21), for relatively moving the first and second members (30,33) from the first to the second member position and/or vice versa depending on the dimension (da, ha; db, hb) of a cartridge (1a; 1b) to be received in the seat (30,33,14) and extracted.