he SPK-C611 6.5" Two-Way Open-Back Round Ceiling Speakers (Pair) from Kramer are a pair of two-way open-back speakers designed for mounting in the ceiling.

Each open-back ceiling speaker is supported by a C-ring and two tile rails. The tile rails prevent the speakers from falling if the tile itself comes out or falls apart, as their ends catch onto the T-grid. When mounting onto the ceiling tiles, use both supports. When mounting onto a sheetrock ceiling, the C-ring alone is used to reinforce the ceiling material.

Lastly, they have an infinite baffle design and aluminum grilles.

The SPK−C611 is a pair of two−way open−back speakers designed for mounting in the ceiling

6.5" (65.1 mm) polypropylene cone woofer

1" (25 mm) Ferro-fluid cooled tweeter

They have white baffle with aluminum grilles and are UV treatment compliance. They include locking arms for quick ceiling installation

Each open-back ceiling speaker is supported by a C-ring and two tile rails. When mounting onto a sheetrock ceiling, the C-ring alone is used to reinforce the ceiling material