Bosch L-RACK-S Expandable Storage Shelf for use with L-RACK Click and Go Storage System Single-Click Stacking: Easily lock tool cases together for easy transport and handling Expandable Storage (L-RACK-S): Attach L-RACK-S to any L-BOXX or other L-RACK-S Works with i-boxx53, i-boxx72 and LST72-OD Utilize L-RACK anyway you choose: Add additional storage to your current L-BOXX's or create your own personal L-RACK configuration of shelves