JICOOT Portable breathing exercise device for lungs, Breathing trainer with Resistance Adjustable, Lung Trainer with excellent quality silicone,Easy to Clean and Use, Improve Breathing Capacity and Endurance Product Description: Control your respiratory health with the respiratory trainer, a high-quality respiratory exercise device designed to adjust breathing rate, enhance exercise endurance, and improve cardiovascular function. As an effective solution for sleep apnea and stress relief, this device improves sleep quality by reducing breathing difficulties and promoting stress relief. Specification: Material:Silicone Color:Black Size:Approx.5cm/1.96''x10cm/3.94'' Package Includes: 1x Breathing Exerciser Note: 1.Please allow 1-2cm differs due to manual measurement. 2.Due to the different display and different light, the picture may not show the actual color of the item.