OK, I dug out the manual. It says it is for the VSX-5700S and VSX-5600, and it also says "The functions of both units, VSX-5600 and VSX-5700S are identical".
The section on remotes shows a different remote for the two models; maybe that's the only difference.
Specs:
Amplifier section
(POWER AMP IN)
Continuous average power output of 105 watts*
per channel, min., at 8 ohms, from 20 Hz to 20,000
Hz with no more than 0.008 %** total harmonic
distortion (front).
* Measured pursuant to the Federal Trade Commission's Trade
Regulation rule on Power Output Claims for Amplifiers.
** Measured by Audio Spectrum Analyzer
Continuous power output
Rear ... 25W + 25W (1kHz, 0.08%, 8 ohms)
Center..25W (1kHz, 0.08%, 8 ohms)