jinamart glass food storage containers, airtight & leak proof bpa free lids, (set of 4) lunch box - 2 bento boxes, 2 full containers, 4 lids jinamart 9 piece set: 4 glass storage containers including bento box with 4 lids for meal prep, for food storage or to pack lunch to-go; two extra lids added made of premium glass: crafted from borosilicate transparent glass, which is the same glass which the pyrex glass brand is made of; this type of glass allows for a very low coefficient of thermal expansion, which means it will not crack under extreme temperature changes and it's safe to transfer from freezer to oven in instants; glass containers do not absorb stains or smells, making it an excellent choice for acidic foods