Stake Sides, Stakesides, Stake Gates, Gates, Stake Bed, all of these work to describe the "fence" we build around the outside edge of a flatbed truck body to hold in cargo and keep it safe from coming off the bed during travel. They also allow us to lash cargo down by having something sturdy to do that with.
Probably the most common Stake Side or Gates are made with steel posts (can also be aluminum) that are shaped to mount into a specifically designed pocket in the outside frame of the flatbed. To this are attached wood, steel, composite or aluminum slats. These assemblies are most often removable in sections so they can all be removed when that need presents itself, or just one or two removed to access cargo in that area. These slats are mounted in a variety of ways, some with space between them as in the first picture below on the left, and some without spaces, like the contractor style gates on the right In addition, you can also get solid plywood, steel, composite or aluminum sides as are used in the Landscape body
The most common height is typically about 40" which is just a bit over cab height. 48" high is common on medium duty or tilt-cab trucks as they have a taller cab. The shorter gates as in the contractor style gates work very well with the tapered headboard and have a clean look.
However you might like your Stake Side Gates to be used, we are happy to build them to suit.