An amazing alternative to a candle. Each pack contains 6 cubes of scented gorgeousness. You need to pop a cube out and place on the top of an oil burner and place a tealight underneath. It will warm the oil in the wax and slow release your favourite fragrance into the air.  It's difficult to assess how long each cube will scent for, as it depends largely on the burner you are using, but reviewers tell me that they just last & last...