The Shure A901-R-TB Tile Bridge allows you to mount an MXA901-R ceiling array microphone (available separately) in drop-ceiling tile grids. The tile bridge rests on the ceiling grid s T-bars above the tile and the ceiling mount installs in the tile bridge. When finished, the microphone sits nearly flush with the ceiling. The mount works for ceiling surfaces that measure from 0.375 to 1.25 thick. The package includes a tile bridge, ceiling mount, round VESA mount, support arms, and screws.