Backpack/Helmet/Vest/Rifl e: Dollar Tree Final Faction
Head: Custom Cast Part
The Rest: Marauders Task Force Parts

This figure has a lot of dollar store parts. Dollar Tree currently has an action figure line: "Final Faction." It's basically futuristic military against aliens. The line is fairly large and they have some cool stuff, but it's a bit lacking in quality. There's nothing wrong with that, of course. I think some of the product is great for parts. The parts I have on Sci-Fi here are the helmet, the vest, and the backpack array.
Anyhoo, I just happened to get a germ of an idea one day when I was trying the pieces out to see what might work as a custom. Putting different pieces together sorta looked like Star Brigade. I noticed that the vest had almost the same shape as Sci-Fi (minus the very large shoulder pads). Now, of course this custom only very loosely looks like Sci-Fi V4, but hopefully the spirit of Sci-Fi is in there.