Concealed fire sprinklers are somewhat like pendent fire sprinklers; however, they're located within the ceiling and they're hidden by a cover plate. Once the cover plate is installed, you can't see the concealed fire sprinkler at all. The cover plate will fall off at a temperature about 20 degrees lower than the fire sprinkler, allowing the deflector of the concealed sprinkler to drop and be exposed to the heat from the fire.

While the finish of the cover plate might concern you more than the finish of the concealed fire sprinkler itself, these fire sprinklers are available in brass and are available in quick response and standard response. Word to the wise: whatever you do, do not paint fire sprinkler cover plates.