This Cylinder has a very nice finish inside and is ideal for the free flowing of a piston. I'm not sure if there's a way to prove this but I would venture to say that it possibly could improve ROF slightly due to the piston's easier movement with minimal friction.
Only reason it doesn't deserve 5 stars is because it's aluminum, which is much more prone to bending. So if you're not careful with it (for example if you clamp it down like I did with my stock brass cylinder to work on it, which was the reason I bought this one), it could be slightly crushed and the piston will have incredible resistance when passing the crushed part of the cylinder.
Overall, good product. Does it's job good.
ZCI Full Cylinder Aluminum (Type 0)
Date Added: 03/30/2013 by Joshua Epstein