Independent, Stackable - 4 compartments can be combined in different order and any quantities, can also be taken separately.^ Safe and healthy material - Food grade Premium quality BPA free PP material, Nontoxic.^ Capacity - 4 layers design, you can put quantity of milk powder to be taken at one time in each layer box, you can carry 4 times of milk powder for baby outdoor need, very convenient and practical.^ Multi-purpose - It also can be used as snack cups and baby foods container, perfect for storing oatmeal, cornflour, nuts, candy, fruit and more food.^ Easily clean & carry - Portable, perfect for travel or on the way. Narrow footprint means it can be stored easily in bags or bottle/cup holders.