Right the 500 watts is the amps peak output whereas the 200 watt is its RMS output which is what it will on average constantly output.
Quote by Kendawg4TooL
You know you're a bassist when you think a guitar is just some freaky type of short scale, six string bass.

This is The Central Scrutinizer......
That Fender "cab" looks just like my Fender 300 watt BXR combo with the amp ripped out of it. I'd bet about $10 it is. should be a good speaker, if it is not worn out. Can't vouch for the head but bet it would sound better if it was still intact BXR instead.
Guitar & Bass