MeshGuard works with the original Screen Tight system by using the same trim cap for a seamless finished appearance. However, you can use MeshGuard as a "standalone" system below the rail with another system above. As an example, here is a photo of MeshGuard below and Mini Track above: 

MeshGuard is a system of components — not just the screen — and usage of all the components is required. MeshGuard mounts to wood structures so the free-standing posts created with Fast Track or Screen Wall are not compatible.