Here are a few key differences between the Smok Nord 4 and Nord 2:
The Nord 4 is slightly larger than the Nord 2 (104.9 x 33.7 x 24.4mm vs. 95 x 30.5 x 20mm).
The Nord 4 has a larger battery than the Nord 2 (2000mAh vs. 1500mAh).
The Nord 4 charges via a USB-C cable, whereas the Nord 2 uses a standard USB charger.
The Nord 4 has dual airflow wheels to customize the user’s draw. The Nord 2 does not have this feature.
The Nord 4 has an output wattage of 5-80w. The Nord 2 has an output wattage of 1-40w.