Sega CD Metal Shield

I just got a Sega CD, but it doesn't have the metal shield that goes underthe genesis, and it doesn't have the extension bar for an old model genesis. If I use either model genesis, will anything go wrong cause the metal shield isn't there? Also, What if I use the old model genesis without the extension bar...will anything go wrong with that?
It's a model 2 Sega Cd...I thought that was kinda evident cause I mentioned it not having the extender bar for the model 1 Genesis...
you can get one at sega parts....but you dont really NEED it. its either rf shielding or a heatsink....cant remember which but it works fine with or without.