Pads w indents

[FMINUS]

Whats the difference between pads that have the circular indents and the ones that dont?

And can I use a 5inch plate with a 7 inch pad?

 

[Rsurfer]

Its called closed cell, meaning that the foam in the circle will not absorb product. Creates less heat which doesnt matter for a pc, but will cut heat down on a rotary. I guess a 6" plate would be better for a 7" in pad, but it will probably work on firmer pads.