Looking to the grinder on the right, note the indicator lights. The Type B has a single push-type switch in the place of the screw shown on the left; you press it by pushing the portafilter against the switch, conveniently using only one hand. Tapping it once selects the single dose (one cup indicator illuminates), tapping it twice selects the double dose (two cup indicator illuminates). The same switch acts as a momentary button on the Type As (the "hand" button shown earlier). That is, press and hold the Type Bs push-type switch instead of releasing it immediately; the grinder will run and the dosage indicators will flash to make it obvious its in "momentary grind" mode. Very nice!