The Horserail® tensioning spoolers have no sharp edges and almost disappear in a long fence line on your horse farm. They tension up your fence rails, so they are nice and straight. The metal pins keep the fence rails tight all year long and the spooler from releasing the fence rails. When properly installed and tensioned correctly, each fence rail is straight and resembles a traditional post and rail wooden fence. Each spooler is easy to install and simple to use. They can also be used to splice your Horserail® fence. Simply slide both ends of each rail into the spooler and tension.