This wire shelving has 4 tier shelves,and all of them are height adjustable. The shelving unit is made of steel wire shelving.The weight limit for each shelf is 150 pounds, and the total weight limit for the entire shelf is 600 pounds. Features: The shelf height can be adjusted to any height you want, suitable for storing items of various heights The shelf is equipped with castors, which can be moved freely, and the castors can be locked at any time The storage shelves provide an enormous amount of space for you and no occupy too much space.You can use this wire shelving in the kitchen bedroom garage and more. Tools, books,household appliances and other things can be placed on this wire shelving.