Gold's Gym 28oz BlenderBottle Classic Shaker Bottle. . Patented mixing system uses 316 surgical-grade stainless steel Blender Ball found only in BlenderBottle brand shaker cups. Patented loop top, ergonomic flip cap, and tapered spout. 28-ounce capacity (Note: measurements only go to 20 ounces). Dishwasher safe, BPA- and phthalate-free. Perfect for protein shakes, smoothies, pancake batter, and more.