Leviton Hospital grade 20 amp outlets?


Are there two types of this outlet? One nickel plated and another brass plated? Which one is better suited for audio use? I have used the 8300 nickel plated version. What is the part number for the brass plated version?
nerspellsner
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Check out Oyaide gold outlets as they are very smooth and better than the mentioned ones above.
The Leviton Industrial Receptacles PDF gives the catalog number as L8200 for 15amp and L8300 for 20amp Hospital Grade non-plated brass contacts. The mounting strap is also non-plated brass.