1. Made of medical grade PVC. 2. Available with 7'anti-crush tubing. Tubing length could be customized. 3. Two colors for choice: green and transparent. 4. Green diluter is for 24%, 26%,28% and 30% oxygen concentration. White Diluter is for 35%, 40% and 50% oxygen concentration. 5. Oxygen concentration: blue24%, yellow28%, white31%,green35%,pink40% and orange 50%. 6. Adjustable nose clip. 7. DEHP free and 100% latex free available.