Glass Bulb - 2.8, 4.2, 5.6, and 8.0 K-factor Horizontal Sidewall Sprinklers and 5.6 and 8.0 K-factor Vertical Sidewall Sprinklers. Standard Response, Standard Coverage: Where standard response, standard coverage horizontal sidewall sprinklers are specified they shall be of an all bronze frame construction with brass deflector. Sprinklers shall have a 5mm glass bulb thermally sensitive operating element, and rated for a working pressure of 175 psi. Sprinklers installed in areas without a finished ceiling shall be of a bronze/ brass finish and shall be of an appropriate temperature classification for the hazard. Sprinklers installed under a finished ceiling shall be a horizontal sidewall style sprinkler with an escutcheon of the same specified finish. Sprinklers shall be UL listed or FM approved. Standard response, standard coverage sprinklers shall be of the GL-SR/SW Series; as manufactured by Globe Fire Sprinkler Corporation.