In one example, a shelf includes a shelf lock positioned within a spring retention pocket of the shelf. The shelf lock includes a main body that includes a spring retention slot to accommodate a spring and an opening to accommodate a pressure component. The shelf lock includes a retractable tab to be inserted into an enclosure to prevent movement of the shelf when mounted in the enclosure. The spring to exert an outward force to insert the retractable tab into the enclosure and the retractable tab to be retracted by an inward pressure.