Brandon is correct however it should be stated that those speakers can only handle anything over 600 watts for short periods of time. The speaker will not handle a continuous 1200watts and will blow if you try.
the RMS power handling tells you how much continuous power the speaker can handle without thermal damage. the peak rating tells you how much the coils can handle in a burst without melting. generally match the RMS rating of the sub to the RMS rating of the amp, at the given load.