high quality Reliable material:portable adjustable muscle trainer is made of trustworthy ABS material and silicone,which is soft and comfortable and can bring you a comfortable wearing experience.Improve strength breathe trainer can provide comprehensive muscle training for different users.Portable and Compact: You will receive 4 different colors of respiratory trainer, each measuring approximately 3.94 x 1.96 inches,the suitable size variable settings trainer is lightweight and easy to carry, convenient for you to use anytime and anywhere.Daily Exercises: The improve breathing trainer is a necessity for sports enthusiasts,the adjustable breathe trainer is suitable for athletes,yoga,fitness,running,and there are enough that you can share with your family and friends.The fitness breathe trainer is a great addition to your training or exercise program.Easy to Clean: portable adjustable exercise trainer is individually sealed and the resistance adjustable exercise device is easy to clean and can save your cleaning time. Be careful with sharp packaging, please open it carefully.Adjustable Resistance:portable adjustable trainer is equipped with a rotary valve and adjustable resistance settings, which is easy to adjust, and the resistance strength of the portable adjustable exerciser muscle trainer can be adjusted by rotating left and right to meet your different needs.