About a year ago Furman Sound introduced their updated Series II line
of power conditioner and distribution centers. The PL-8 Series II
included some very important upgrades from its predecessor. The
original PL-8 had a traditional style surge suppressor circuit that
would sacrifice itself if the power surge was great enough to damage
equipment plugged into the unit. This was a very good insurance policy
for your rack gear, but did require that you send the PL-8 in for a
replacement of the suppression circuit. Unfortunately, this also
temporarily shut down your rack system, or at least left you
unprotected, while the PL-8 was being repaired. However, now with the
incorporation of Furman's new "Series Multistage Protection" (SMP)
technology, you will no longer need to worry about a surge causing the
power center's circuits to be destroyed.

Click the link below to read more:
http://www.guitargearheads.com/modules/news/article.php?storyid=101