Each pair can be played in different volume levels and different rooms can play different music delivered by 2 different Amplifiers through the switch control. In addition, this unit allows you to switch on or off any number of the speaker pairs connected to the 2 different Amplifier inputs. Manual impedance correction can be easily set on rear of unit using a flat head screwdriver from 1, 2, 3 to 6 or 7 to 10 speaker pairs. This will safe-guard your valuable amplifier and speakers from damage because of excessively low impedance when all 10 speaker pairs are switched on and playing simultaneously. The item "10 Zone 2 4 6 8 Pair Speaker Selector Switch Switcher with Volume Level Control" is in sale since Monday, May 13, 2019.This item is in the category "Consumer Electronics\TV, Video & Home Audio\TV, Video & Audio Accessories\Splitters & Combiners". The seller is "specialty-av" and is located in Lakeland, Florida. This item can be shipped worldwide.