The Systainer³ insert box system is built on a 50mm x 50mm (2in x 2in) grid. This 3x6 insert box occupies 18 grid units — 3 units deep by 6 units wide — so it measures 150mm x 300mm (6in x 12in), the largest insert box available. Roomy enough for so many items for the workshop, and combines easily with other insert box sizes to build the exact layout you need.Every Systainer³ that uses insert boxes — the Systainer³ Organizer, Sortainer and Combi — can be thought of as its own grid of these 50mm units, which keeps the math easy when planning your compartment layout. Insert boxes fix securely into that grid to divide the space and keep your hardware and small components organized and separated for storage and transport.See the Technical Specs below for the grid size of each.