The J1 Upgrade kit from Snapmaker is the perfect addition to your J1 3D printer. The fan ensures that you can cool your 3D prints while printing at high speed. In addition, the fan also reduces the ambient temperature in the printer. This upgrade kit eliminates the need to remove the top panel when printing with PLA and reduces the bumpy overhang when printing with PLA. In addition, the fan shaft is narrow, so it does not protrude very much.