Delicate and soft diving cloth, non-friction, sweat-proof and breathable, lightweight and compact, sweat-absorbing and shock-proof, no peculiar smell, environmentally friendly. It is stretchable, bendable and foldable. At the same time, it fits tightly to your arm for more comfort.2. Fit: Humanized adjustable high-elastic bandage design, fit tightly, strong and durable, anti-shedding, easy to wear. Breathable back, thickened and breathable mesh design, comfortable to wear and sweat-wicking.Design- Jogging Arm Bag Double Adjustable Velcro Straps Fits Any Arm Size from 22cm to 40cm.4. Safety: closed zipper, lettuce gum. High practicability: It can store personal items such as mobile phones, documents, bank cards, keys, and change.5. Double pocket design: The armband design of the running phone holder can fit the arm or wrist at the same time when needed.