The rack-mounted cage, also called the square-tube cage, is a common non-standard warehouse cage. It adds square tubes to the legs of a standard cage so the cage can sit directly on rack beams. There are a few ways to build it: add square tube, angle steel, or bent fittings between the two feet of a regular cage; or remove the cage's original stacking feet and join and weld square tubes directly. The goal in every case is to let the cage rest steadily on the rack beams. One real-world point to watch: If the racking is already built and the beams have no reserved stacking tubes, add stacking square tubes to the bottom of the newly purchased cages; If the racking is not built yet, you can save cost by using a standard cage's four feet and instead adding cage stacking square tubes to the rack beams. The two options differ in cost, so Xintongnuo advises deciding how the cages will sit during the rack design stage.