This is also a popular type of deer fence kit. They are designed to contain or exclude medium to large animals but do not include a rodent barrier. These kits include extra fencing to overlap on top of the ground and to pin to the ground with included ground stakes. This covers changes in grade, peaks and valleys in your landscape. This prevents deer from being able to push up under a fence for access. These kits also make it very easy to have a nice looking finished product; the top fencing gets installed at the top of each post while the bottom fencing takes up all the changes along the ground.
Size example: 7 1/2 x 300 refers to a fence kit 7 1/2 foot above ground finished height that is 300 linear feet long . Linear footage is a measurement of footage as if you measured with a tape measure. If you have a large area to measure, measuring wheels are available in most hardware stores. Have a surveyed map of your property? Most have linear footage that you can scale from with a ruler.