Nonautomatic Water Mist Nozzles (Open) : Nozzles that operate as an entire system or grouping of nozzles, containing open orifices and activating the water flow to the nozzles by an independent detection system
NFPA 750 Standard on Water Mist Fire Protection Systems, 2003 ed. https://www.nfpa.org/Assets/files/AboutTheCodes/75 0/750_FKT-AAA_SDAgenda_01-13.pdf, (Std: Wtr Mist Fr Prac Sys - Amer) {346 NFC}