Measurements: Wire Metal Ball Diameter: 2.1 inch Safe-grade Material: Our whisk balls are made of food-grade 304 stainless steel, durable and rust-proof. These shaker balls are safe and healthy to be used in mixer bottles or cups. Useful Shaker Balls: Our 304 stainless steel shaker balls help a lot to mix all ingredients thoroughly, no chunks any more and save time while mixing formula at feeding time Easy to Use and Clean: Just put the stainless steel whisk balls in the bottle or cup, then shake the bottle or cup uniformly. It is also very easy to clean the shaker balls with water or put them in the dishwasher after use. Make Your Life Easier: You can use the shaker balls to blend smoothies, salad dressings, protein shakes, fiber drinks, sport mixes, formula, wine, coffee and other creations. The stirring balls are ideal gadgets for home, fitness people on the go, gym, office, café or restaurant. Package Includes: 2PCS 2.1” Shaker Balls