Crown PL3--unusual?

Not that I have seen LOTS of Crown Power Line amps, but this one has 3 sets of speaker connects. The one on top that is usually found and then two more (1 and 2) connections. The main one works regardless if the speaker selectors on the front are pressed or not. And the 1 switch and 2 switch activates the 2nd and 3rd set of speaker outlets as you'd expect.

Has any ever seen this setup on a Crown Power Line amp before?

 

The top speaker outputs are bridged to mono and the bottom two, ie left and right, are stereo outputs. The switch, top right, switches between mono and stereo. Interesting amp, Google it and check the specs.

 

The top speakers CAN be bridged to mono, they are now in stereo mode. I have googled it. All information I find is on these amps with only the top speaker outputs.

I have a PL4 that only has the top speaker outputs, which also CAN be bridged for mono.

 

Most I have ever seen look like this: