Upon activation, 1 coin will be consumed, and will have the same function of a Slot Machine. It can be used infinitely as long as the player has coins to spend.
Using this in a boss room to spawn a fly after defeating the boss will enable the player to leave the room and come back, facing another boss battle and another item spawn.
The type of heart dropped is affected by the current room (like a normal Slot Machine), e.g. an eternal heart if in the Cathedral Room.
VideosEditThe Binding of Isaac PSA 2 - The Portable Slot(03:04)