A special glycol/water-based fluid, Unique fluid is for the Unique haze machine. Unique fluid ensures an optimal haze and minimal fluid consumption. Please note that haze from a Unique has a very long hang-time. To make your own calculations: the Unique consumes 1 ml of fluid per minute for every setting of 10 on the pump (uses 2 ml/min with pump set on 20, 9 ml/min with pump set on 90, etc.)