UPGRADED LEAK PROOF SYSTEM - Tired of messy? Our Twist-Lock system features two silicone gaskets to create a leak-proof seal. This means no more sticky leaks and less clean ups even if the toddler dropped it, designed for active toddlers. ***Warm Tips***:When using the straw, please DO NOT shake the cup upside down to avoid leaking. DOUBLE-WALL VACUUM INSULATION - Double walled vacuum insulated 18/8 stainless steel keeps kids water or smoothies cold up to 12 hours. Sweat-proof design keeps kids cool while playing. Cheers to hitting those milestones! SAFE FOR TODDLERS - The durable insulated toddler cup is made from kid-friendly materials, all parts are BPA-free, BPS-free, and phthalate-free. The 100% silicone straw with stopper is gentle on gums. Non-slip silicone base to minimize skids and tipping. BUILT TO LAST - Made from durable kitchen-grade 18/8 stainless steel, so they're puncture- and rust-resistant. Enough to stand up to everyday wear and tear, and great for busy kids with active lifestyles. signice straw cups are the perfect addition to kids' daily routines. EASY TO CLEAN - Top rack dishwasher safe or wash in warm water using mild liquid soap, rinse thoroughly with clear water. Do not microwave. Signice kids straw cups come with a limited lifetime warranty against manufacturing defects.