something like this https://www.amazon.com/Monoprice-108231-Speaker-Selector-Control/dp/B007N43T5Y

Allows you to enable or disable a pair of speakers but also individually adjust the volume per speaker pair.

Any difference between the one you listed versus these?

1. 2 channel speaker selector

2. 4 channel speaker selector

Only asking because I can't see the back of the amp switcher you listed on amazon .