This is a PSU air duct frame I designed for my Lian Li Dan Case A3. It should work with any SFX PSU (I am using it with the Corsair SF1000).
Its purpose is to guide hot air from the PSU out of the case (through my modified front plate) instead of blowing it back into the case. The duct is mounted with help of the 17mm standoffs and the rubber rings that come with the Lian Li Dan Case A3 (see pictures).
The author marked this model as their own original creation.