Our coffee mug is made of durable borosilicate glass. The thermal silicone sleeve and PP lid are Food-grade and BPA-free. It’s free from toxins and chemicals, will not taint the flavor of your coffee.You just need to flip the cap on the unique design lid and drink from the drinking-hole on it. The hidden air-hole is applied with smooth and suitable drink flow. With a silicone seal ring and plug, the splash-proof lid will mean you avoid accidental spills while walking or driving.Large Grip area with Anti-scald silicone Sleeve, can protect your hands from heat. Textured design provides a great grip to prevent accidental slipping.