The 2018/19 Arsenal third shirt is made by Puma.
The Original shirt is green watercolor, while the Fake ones are mostly sky-blue.
The Arsenal crest is hugely deformed on the knockoffs (it’s much larger than it should be), as the Puma logo is slightly deformed and out of scale on the Fake shirts.
The size square inside the neck leaves is grey on the Fake ones, and dark blue on the Original shirt.
The inside of the shirt is green watercolor on the Original ones, and it’s white on the fake ones.
The Puma “Authentic Product” black tag is put on the left bottom on the Fake shirt, while it's actually on the left side in the Original one.