Aluminum open cell ceiling tiles are designed to lay onto 15mm Tee Grid. These tiles can be used without any tee grid system also. Access is gained by simply lifting the tiles out of the grid. The new Lock-in system features open cell ceiling panels with no frame or border around them. The panels simply connect to each other with easy lock in system of main and CMS. When grid system is not required, the Lockin system of Main and Cross provides architects and designers with additional flexibility, especially in customized sizes and different colors.