This is Star Wars The Black Series Titanium Series #05. These mini diecast set contains Finn's Stormtrooper helmet and First Order Tie Pilot helmet. This set is rarely available at some toy stores and just got lucky to have found one at Toys R Us.
I mentioned before in my recent post of #03 Darth Vader and Stormtrooper mini helmets regarding the base if they can detached, yeah it's possible because here in #05 Titanium Series, the tie fighter pilot's base is separated inside the package. You just snap it inside the helmet and it holds firmly. I saw a video review of Poe Dameron's TBS Titanium Series helmet being tried on Luke's Sideshow figure but they're kind a small to fit it. Of course I tried detaching the base but it was stiff so I just quit.
