It's about 15w rms @ 20% distortion. Honestly, it not worth using for anything. Just leave it there in case some poor fool wants it.
When you say the installer left it, did they at least bypass it? Since this amp is external to the factory HU, the speaker wires at the HU go through this amp and them out to the speakers. Everyone I know that has heard their exact system with the amp connected vs. bypassed has noticed a significant improvement in sounds quality with that amp bypassed. It just involves a simple harness, but most installers don't use it unless it is requested.
Aaron
