Besides outstanding strength and durability, these storage containers have double-sealed lids so that once they are closed nothing can get in – or leak out. Manufactured to our specifications, they are made of Tritan copolymer, an advanced composite material that looks like glass but withstands impact, abrasion, extreme temperatures, and everyday wear and tear unlike any ordinary plastic. You can drop the container, step on it or wash it repeatedly in a dishwasher without harming it in any way.