A client with increased intracranial pressure from a brain tumor is admitted to Neuro iCU. The health care provider (HCP) prescribes 25\% mannitol 20 gram intravenous (IV) bolus. The unit stock is mannitol injection 12.5 grams of 25% mannitol in 50 mL water single-dose vials. How many mL will the nurse draw up?