Ykk zippers, only the best :)
As for the specific treatment process, our tannery treats that as proprietary. But it does behave similar to scotch guard. When we exhibit at retail shows we use a side of leather as a table cover, and have spilled diet coke (basically batter acid LOL) on it without any issues. It takes several hours for any non oil based liquid to penetrate the surface of the leather.
Hope this helps,
Chad
And who makes the zipper? YKK or someone else?