The free spins may be given on certain slot (such slots are referred to as Free Spins Slots) or on all slots by a certain manufacturer, most often, online pokie games by NetEnt, like 50 free spins on Dead or Alive 2 with no code required, 10 free spins Wolf Gold by Pragmatic Play (wagering for free spins is 50 x, no code required) or 25 free spins on Fruit Zen by BetSoft with FRUITZEN code required.