Yes, you can use that wire, but you should only use it for
runs under 30 ft. I use a similar, but less expensive (30ft. $20) product made by Acoustic Research. Unfortunately, that company seems to have stopped manufacturing it, because I can't find it anywhere.
What I did was run my regular 12 gauge speaker wire, along my baseboards, mostly hidden by furniture. Then I ran the adhesive 18 gauge flat wire up the wall to my surround speakers, and connected the two wires with the
TB18 connectors from 21st Century goods. Doing that allowed me to get a longer (and less expensive) run than I could have gotten with the flatwire alone. When painted to match the walls, it is very unobtrusive.
JohnK, resident knowledgeable electronics expert (& Cleveland Browns fan
) assured me that using only 6 ft. of the 18 gauge attached to a longer run of the 12 gauge would have no adverse effects on speaker or receiver. It made the effective gauge of the entire run something like 12.5 gauge, which is more than satisfactory.