Magnetic cover for air inlet

[jland48]

I have seen these magnetic covers used on youtube and wondered if anyone knows where they can be purchased?

 

[Centercut]

(QTY 2) METAL 4 BALL DETENT COMPRESSED AIR FILL NIPPLE DUST COVERS https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F273326639096

or

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F312154751140

 

[jland48]

Thank you Centercut, these should do nicely.