This is a custom reskin of the PPK in Zombie Panic! Source.
This includes 2 types of skins:
Default black ppk with wooden handle and slightly updated black metal and custom magazine.
A nice brushed metal silver ppk with wooden handle grip and custom magazine.
This custom ppk will only work if you know how to take ZPS and put it as a source mod rather than the one off of steam. Please follow the link of the tutorial if you would like to find out how to get this skin to work.