So I found an ABS-Flag for the monoprice Select Mini V1 and found out that it wouln't fit the V2.
I designed one for the V2. You just have to print it (Doesn't matter if ABS or PLA) and push it into the outlet of the fan. Make sure your clips are attached to the side of the fan. They will provide the needed tension so the flag doesn't fall out on its own. It prevents the cooling of the nozzle and your printer will be able to print ABS way easier and better!

Designed with SolidWorks 2015