CM Computer Case Fan Dust Filter PC Mesh Filter Cover Grills with Magnetic Frame, Black Color (120 x 120 mm (6 Pcs))

These are exactly 120mm squared. Very nice for sticking on the intake of an ATX power supply (if running externally.The magnetic strip is strong enough that I can place it on a metal surface upside down and it doesn't fall off. I can place it on a vertical surface (power supply intake) and it doesn't slide down or fall off when the fan stops.They're even stiff enough that I could lean one vertically against a 120mm fan that has no case or grill etc on it's intake. (obviously there's no magnetic attraction there, but the fan holds it on)These will save me a lot of trouble when it comes to cleaning vs disassembling everything to remove the dust accumulation.

I got this to put on top of my av receiver as we have pets and combust green in the house. Works quite well.

My PSU seems to run cooler now that it is not collecting dust nonstop. Our street is being worked on so there is dust in the air all the time when we open our doors.