Tracker Markings : Stay on track with hourly hydration goals. Hourly markings on the bottle to help you keep track with hydrating throughout the day. Flip to Sip: Simple to use flip us straw, great for kids and adults, allows for quick and effortless drinking, perfect for workouts, hikes, and busy days. Durable & Safe: With a spill proof secure screw cap closure. The bottle body is made from ECOZEN, a bioplastic material derived from renewable resources. Easy Clean: The bottle has a wide opening and removeable straw for easy cleaning. Confidence for parents, safe for children because it's BPA free. Suitable for adults and children 48+ months Up.