The lid is an attractive, safe, and practical material that gives a premium look that sets itself apart from any other tumblers. The lid is well stationed on top that prevents it from leaks and spills while also being clean. Food Grade silicone is a non-toxic type of silicone that does not contain any chemical fillers or byproducts, making it safe for use with food. The 20 oz Glass Tumbler is made of Food Grade. silicone with a 2.9"- 7.4" design, which can fit in most car cup holders. The sleeve also provides a grip that stops your hand from slipping and dropping the object to the ground and also stops your hands from getting wet from condensation.