Round Magnetic Vent Cover AC / HVAC

Round magnetic vent cover for AC / Heater / HVAC vents. These are common for rectangle and square vents, but was not able to find any for round vents. This includes a few different sizes and styles. They fit 12" vents (240mm cover), and 9" round vents. The magnets used are 6 x 3 mm and should press in and stay without any tools or glue.