Nubys Clik-It GripNSip will stop parents from worrying about spills and leaks! The lid clicks when twisted into place, so you know its securely attached to the cup base. Nubys Clik-It GripNSip cup has a soft silicone spout designed to prevent drips and spills. Little ones are animated and active, even while holding (or occasionally dropping) their drinks. Thats why Nuby designed a cup spout 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.