Material: Made of high durable PE+PP & Silica gel; Product weight: 100g /1000g maximum fully loaded water filling weight. Our dumbbells material is carefully selected, safe and non-toxic, wear-resistant, acid-base resistant, low temperature resistance, and maximize its service life. It has excellent air tightness and because of its softness, you will not hurt the floor when you accidentally drop it. New concept: Novel and practical, weight adjustable, the amount of water is controllable and depends on your own needs. Adjustable dumbbell is easy to assemble, easy to deflate and easy to carry or storage. Precisely design: Double seal design to prevent leakage, besides the double spiral waterproof cover, our dumbbells also built-in silicone sealing plug to double sealing-up, so don't worry about any water leakage. Anti rolling design is adopted at the bottom, and a close imitation rolling buffer zone is adopted to avoid rolling caused by ground tilt or external force. Act on: Dumbbell is a necessary equipment for people who love fitness. It can exercise muscles and perfect the muscle lines of arm and back. Scenario: Lightweight and portable, you can put it at home, in the office or outdoor sports, load walking. Unique design makes it lightweight and space saving, you can exercise all the time to create a perfect body.