Upgrading wall outlets

I just added two 20 amp circuits for my power amps using 10gauge with ground wire. I used Leviton 20A Heavy Duty Outlets.
03-22-10: Coxhaus

Coxhaus,

Is the supporting back strap of the Leviton receptacle made of steel?
(Magnetic ferrous material)
.

Thanks for showing me the High Magnetic breakers. It turns out I am using square D as shown. I am thinking of buying a pair of Bryston 28SST amps. I probably will replace my breakers then.
The Leviton receptacle does have a supporting silver steel strap on the back. Why?

I just swapped out a Porter Port for a Maestro outlet, and there was a significant improvement! Detail, soundstage depth and width increase, and I have to say it again, Detail.