<prompt> Which of the following is low flow Oxygen delivery deviceNasal cannulaVenti-maskBag mask ventilationAerosol system  <response>: A nasal cannula is generally used wherever small amounts of supplemental oxygen is required, without rigid control of respiration, such as in oxygen therapy. Most cannulae can only provide oxygen at low flow rates--up to 5 litres per minute Lmin--delivering an oxygen concentration of 28-44. Rates above 5 Lmin can result in discomfo to the patient. 