Bearing Replacement Shields

[RC_Noob]

I'm very curious, but does anyone know where you can buy those rubber shields that go over the bearings? Seems like fasteddy, arrma, traxxas and few others all seem to have a rubber shield for the bearings. I've repacked some bearings with grease before and I can never take off the shields perfectly so they stay in perfect shape and was wondering if anyone knows where they actually buy those little rubber bearings shields.

 

[GamwToInsomnia.gr]

If you search Ebay, you could find some shields, but for specific bearings for motorcycles and others.
It would be nice to change this sealans, but for the miniature bearings for our cars, i think it would be near to impossible to find parts!