How are the burners installed into the countertop?

How are the burners installed into the countertop?

All units in our assortment are mounted onto an established module with a predetermined gas connection. The module is positioned from beneath through cutouts and secured from above by screwing it to the burners by means of the heat shields.  Two joists are supplied and are mounted  to the inside of the kitchen cabinets to provide support to the underside of the module.