The PMV 2001 (Purple Color) (15mm I.D. / 23mm O.D.) is identical to the PMV 2000 (clear) except for its color. This valve is lightweight and opens with even less resistance than the original Passy-Muir Valves. It can be used in-line with mechanical ventilators in conjunction with non-disposable, flexible tubing, such as a 22mm silicone adapter. The purple color is easily recognized by staff and caregivers.