I use the electric Tape also. It's called Horse Guard Fence Tape and they do have a website, though I can't remember the address. Maybe do a search? I use 2 strands but one will actually do the job quite well since it is so incredibly tough, visible and effective. In the past 6+ years of using it, we've only ever had one break, and that was due to someone driving over the top of it with a vehicle (thought they'd lowered it enough, but hadn't). I very much prefer it to regular electric wire.

We also have the braided electric tape/wire which is actually a nice sized little pen used for traveling to trailrides/shows and is solar-powered so easy to set up in the middle of nowhere!