The ClosetMaid 30 in. ShelfTrack Standard is exclusively designed for the ShelfTrack hang track and bracket system which allows wire shelves to be adjusted to any height, making storage more versatile in both large and small spaces. Durable metal construction and double-slotted design provide strength and durability. Standards need to be placed no more than 24 in. apart and no more than 4 in. from the end of a shelf for stability.