It's 8ft diameter, and it's just the mat, not the springs. Springs are damn expensive. If you can get a set of springs for R300, you're looking at a bargain haha.
I think the diameter is the same across brands. I bought it for a Bounce King 8ft trampoline, and while the mat has less hoops than the Bounce King has springs, it still worked a treat (I bought two, one to replace the worn mat, and another as spare).
It's a smoother mat than the original Bounce King mat, if that makes sense. It feels smoother and softer under foot.