These 3 parts (makes 4 pieces) replace the existing ones to adapt it to use a standard 60mm Fan. No holes are printed into the adapter and must be drilled since each fan mount is a little different. The fan mount itself is different and positions the fan higher than the original 40mm. The new fan must be mounted on top in order to have bed clearance, so you must also print 2 copies of the Fan brackets since they allow the fan to be mounted on top and adjust the fan angle slightly up. There is no need to replace the 40mm fan, there is no added benefit unless you are switching to a more powerful fan. I damaged my original fans sockets during original assembly and decided to use this to replace it with some of the dozens of existing 60mm ones I have in the scrap pile. I really recommend using a half height \"thin\" fan. I have been using a 12v .22a Evercool Half Height CPU cooling fan with no problem.