What is the zipper made of?

Plastic

Comparison: JC-01 and JC-07

“Pretty much the same jacket. Only difference is that the arms are more longer on the JC-01 and the JC-07 is more wide. JC-07 is pretty much just a shiny JC-01, imo JC-07 is better. The JC-07 is much more softer and less plastic like. The JC-01 is more thicker, not soft and a lot more rigid. Personally I think the JC-07 is nicer feeling and better fitting. About the sleeves, JC-07 is a less wide and not as long. Fits 10x better than the JC-01” original post

Yeezy Jacket JC-07 Sizing

Size 1

• Length: 26″ (~66 cm)

• Pit to pit: 23″ (~58 cm)

• Sleeves Length (from collar): 32,5″ (82 cm)

Size 3

• Length: 28,5″ (~72 cm)

• Pit to pit: 31″ (~79 cm)

It seems to have similar sizing, length and width, than the Yeezy Jacket JC-01 (see comparison photos in the gallery), at least for Size 1.