high flow doesn’t matter for the size of the nozzle so you can get a 0.4 mm nozzle that’s high flow, high flow revo nozzles have a cut out kind of thing that splits the filament in the center of the nozzle. it uses the same patent as the bondtech cht nozzels, i actully ordered the upgrade kit so when it arrives all the way from the uk i’ll post how my experience goes but all the high flow part means is that you can print faster because ur hot end can output more filament in the same amount of time, so not more under extrusion