The SP-93-V speaker selector with volume control will allow you to use two stereos with up to 6 speakers (3 pairs) placed around the house, restaurant, office, warehouse etc. You can turn each set of speakers on and off, and adjust the volume for each pair as well. The input for the SP-93-V comes from your stereos, amps, receivers, etc. This just means you take the speaker wires from the back of your stereo, amp, etc. and plug them into the either input terminals on the back of the SP-93-V. Each speaker pair has independent rotary volume control. Volume adjustment and impedance matching is accomplished through internal heavy-duty multi-trapped transformers for each speaker. This allows complete, independent control of each pair with maximum efficiency and virtually no generation of heat. The built-in precision auto impedance correction and overload protection circuits will safe-guard your amplifiers and speakers from damage due to excessively low impedance when all 6 speakers are playing at the same time. Machined brass gold plated color coded professional grade banana socket connections accept up to 12AWG wires. Dimensions: 2.50"H x 10.0"L x 12.0"W. Sturdy metal enclosure. Passive design, no power required.