checkpoint said at one time they will release a fan kit. but I haven't heard anything new since then...
so I ended up fabricating my own.
I used
(2) 3mmx10 or 12mm grub screw
(2) Tobee standoff front bumber brace from the Pro4
(1) 25mm 5v fan.
I had to drill and tap the mounting holes for 3mm.
simply insert the grub screw and tighten with the Tobee standoff
and install the fan.
an alternate is to find a long enought 2.5mm screw to go all the way through.