Rated Input: 3W, 1W, Rated Impedance: 3.3 kΩ (3W), 10 kΩ (1W), Output Sound Pressure Level: 87 dB (1W,1M), Frequency Characteristics: 150 - 20,000 Hz, Speakers Type 3W Connection: L Class (Fire Law Enforcement Rules of Voice Alarm) on a second signal 92 dB (A) or above in measurement) 1W Connection: Medium (fire fighting law enforcement rule, voice alarm sound measures at 2 signal, sound power level 91 dB (1 W, 1 m) Directional Characteristic Classification X (horizontal/vertical: less than 0° or 60° Q=2,60° or 90 or lower Q=0.8) Temperature range -20 °C to +140°F (60°C)Dust Generating Performance: No dust in measurements of JIS B 9926 Waterproof Performance IPX4 Chemical Resistance Resistance Resistant to Formaline Solvents and Povidone Yode Liquid (Disinfectant) Other Finish in accordance with JIS C 5532 (Speaker for Acoustic System), Frame: ABS resin, Chrome Plated Finish Case: ABS resin, Punching Net: Stainless Steel 139 x 1 04.5 (D) mm Weight: 19.7 oz (550 g) Mounting Hole Dimensions φ 3.9 inches (100 mm) (thickness of plywood equivalent) Accessories: Gasket (silicone rubber) 1, Pattern Paper: 1, Ceiling Mounting Tapping Screws (stainless steel) 4. *Cannot be used in dry sauna and net surfaces where water may come directly into contact with water.