Grating section
From Tardis Wiki, the free Doctor Who reference
The grating section, or upper grating section was the part of a Dalek's casing below the dome and above the weapons platform. (PROSE: The Dalek Generation)
Should a Dalek chose to open their casing, the front portion of the grating section would extend and split in two, exposing the Kaled mutant inside. (TV: Dalek)