To use it, you place the .scs file into your Documents\Euro Truck Simulator 2\mod folder and activate it in the in-game Mod Manager.
These packs add high-detail models to the game, which can sometimes tax system resources if you have many traffic mods active at once.
Jazzycat typically uploads his mods to his official site, Jazzycat Mods, and often uses ShareMods for hosting downloads.
This term (Hungarian for "painted") indicates that the trucks in the pack feature real-world company skins and liveries rather than generic colors.