Features: Breathing exercise equipment to challenge yourself for better exercise and improve overall endurance. Vital capacity - it helps to expand and improve vital capacity without the risk of having to do a lot of aerobic exercise and burning calories. The portable device - Adventurer lung breathing training instrument is very compact. Easy to carry. The adjustable resistance dial makes the simplest task more difficult, and can exercise more intensely according to your needs. It can be adjusted up and down by rotating the valve to change the breathing resistance. Specification: Material: Silicone+ABS Color: as shown Product size: as shown Application: Running, cycling, swimming Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color shown on the pictures. Thank you! Please allow 1-3cm measuring deviation due to manual measurement. Package include: 1 X Lung Fitness Trainer