呼吸练习器
- 宽流量范围为600至1200 cc / sec
- 3个颜色编码球/ 3个室
- 每个室上印有最小流量

Respiratory Exerciser
- Wide flow rate range from 600 to 1200 cc/sec
- 3 color-coded balls/3 chambers
- Minimum flow imprinted on each chamber