From System Sensor, an alternative to bells as a notification appliance is the SpectrAlert P12015K, a 120-volt wall-mount horn/strobe that is UL-listed for outdoor requirements. The P12015K operates in a temperature range of -40F to 150F and is rainproof per UL50 (NEMA 3R). The product was specifically developed to be used in a sprinkler system to provide a visual reference to the alarm location.