No plastic, no metal, no aftertaste. The reusable Glass Coffee Tumbler from Studio Oh! is made of shatter-resistant borosilicate glass coated with silicone, making it both silky-smooth and easy to grip. Topped with a secure, sip-through silicone lid, this vessel offers an environmentally friendly way to bring along your coffee with bold messages and stylish designs to make it fun! • Is crafted with shatter-resistant borosilicate glass for an eco-friendly alternative to single-use containers • Is coated with smooth-touch silicone • Features a snug-fitting, sip-through silicone lid for use on the go.