Dual Ball bearing fan, Long lifetime 50000Hours tested under 40degree temperature
It has two sides, but the side with sticker must be always facing the hotend (not visible when the fan is mounted). Otherwise, the cooling won't work properly.
5V DC 0.1A, This fan is used for Prusa i3 MK3 MK3S MK2/2.5 3D printer Extruder