This is a remix of NeverDun´s beautiful air knife (compressed air diffuser).
It has a smaller hole in the intake, made to be drilled, threaded and to mount an air coupling in.
It also has bigger area between the two parts to seal it tight with silicone or glue.

PLA from http://www.3dprima.com/ printed on my Kossel Mini.
Print 2 of them to make a pair.

Mine is printed with layer height 0,2 and with support, oriented as it is built (with the inside part up).
Print time < 30min per piece.