Bet you can’t guess what this Thing is for. It’s a hop up, or a paperweight, or maybe a very expensive fidget spinner, but we’re pretty sure it’s a hop up. Actually, it’s a 6061 T6 Aircraft Aluminum hop up. We know, “Aircraft Grade” is the favorite buzzword of every airsoft company trying to make a $15 part sound like it belongs on a SpaceX rocket. But we actually machine these Things in-house at PolarStar to +/- 0.002″ tolerances because we’re tired of seeing high-end builds ruined by sloppy, off-spec cast parts. They used this stuff for wing spars and fuselage skins, and now you’re using it in your airsoft gun.