This Perfect Seal 20 Piece Lock & Seal Storage Set keeps dry food fresh longer by creating an airtight silicone seal. Simply twist the lid's knob-handle clockwise to seal and counterclockwise to open. Containers are made of clear plastic so contents are easily identified and the corners are rounded for easy pouring. The modular design is stackable to save cabinet and pantry space. ABS and silicone construction. BPA-free. 20 piece set includes one each of 3-1/2 quart, 2-1/4 quart, 1-3/4 quart, and 3/4 quart containers with lids, two 1-1/4 quart containers with lids, and four 1/2 quart containers with lids. Dishwasher safe.