16-ounce capacity (note: measurements only go to 12 ounces) sleek and durable shaker cup for mixing protein shakes, smoothies, and supplements,Screw-on lid creates leak-proof seal, and secure flip cap with SpoutGuard keeps the mouthpiece clean; wide loop top for easy carrying or attaching keys,Wide mouth makes it easy to add mix scoops and liquids, and embossed markings measure both ounces and milliliters; rounded base for thorough mixing Just push down on the flip cap until it makes a distinctive snap, then shake or stash the bottle with complete confidence that it is securely closed. When opening the cap, the SpoutGuard protects the drinking surface from grimy gym fingers. An extra-wide carry loop makes it easy to take shakes to go.