Tisaks are on every corner throughout Croatia, noticeable by their large red "TISAK" sign.
A tisak is a booth selling a smattering of items from sunglasses and umbrellas to cigarettes and lighters to magazines, batteries and bottled water. They also sell bus and tram tickets, often at a savings of a few kuna per ride.
Tisaks are like convenience stores only on a much smaller scale. In a pinch, they can be a lifesaver.