Nuby’s Clik-It Grip N' Sip will stop parents from worrying about spills and leaks! The lid "clicks" when twisted into place, so you know it’s securely attached to the cup base. The cup has a soft silicone spout designed to prevent drips and spills with a pressure-sensitive TOUCH-FLO valve that helps regulate fluid intake as children drink. As children sip on the spout, the valve opens and allows liquid through. When sipping ceases, the valve closes, ensuring a leak-resistant cup! Whether your little one stays still while sipping, or prefers to keep on the move and hold their cup at an angle, Nuby has you covered. The Clik-It Grip N' Sip holds 10 ounces (300ml) of liquid, keeping little ones happy and hydrated.