Roll-out Shelves have safety interlock.
Press Release Summary:

Original Press Release:
Roll-Out Shelves With Safety Interlock
Roll-Out shelf units are equipped with automatic safety interlocks that lock all other shelves in when one is rolled out. These units are ideal for storing dies, molds, printing cylinders, and maintenance items, etc. Roll-out shelves give you easy accessibility to all items stored. Shelf capacities from 500 to 40,000 pounds per shelf.