The Stanley STST14021 SortMaster Light Organizer is a handy organizing case that everyone should have! This unit features removable dividers which allow for high customization for small parts and hand tools. The special lid structure prevents movement of small parts from one compartment to another. This unit has locking latches which allows you to stack, secure, and transport up to 3 organizers at one time. Also able to stack either back-to-back or front-to-back for easy access.