Hot End Cover (Ender 3 V2).

Print upside-down, 0.24mm, 10% infill. Mounts onto the x carriage rail secured by a screw through the slot. The screw slot allows you to raise the fan duct side by placing something in the groove it sit on (some tissue for example) if it is too low and still get the bolt/screw to go through. One piece for zero assembly required.