High Borosilicate Glass Material: Crafted with durability in mind, these glass bowls resist thermal shock and can handle extreme temperatures, making them safe for the microwave, oven, dishwasher, and freezer. Leak-Proof & Portable: With lids that fit securely, these bowls provide a tight, leak-proof seal to keep your food fresh, whether you're at home or on the go. Versatile & Convenient: Perfect for mixing, baking, serving, and storing, this set offers a solution for a multitude of kitchen tasks. From kneading dough to serving popcorn, GENICOOK has you covered. Heat-Resistant & Practical Design: Withstand temperatures up to 1040°F (-40 to 1040℉), these bowls feature wide rolled rims for easy pouring, a flat bottom for stability, and thicker walls for added sturdiness. Space-Saving & Easy to Clean: The nesting design saves space in your kitchen, while the smooth angles and curved inner bottom make cleaning a breeze.