This virtually indestructible cover (solid for strobe unit alarms) is designed to stop vandalism and accidental damage for surface mounted units. Molded of clear, thick, UV-stabilized polycarbonate material, backed by a lifetime guarantee against breakage in normal use. Unit comes with a spacer with knockouts for mounting over exposed conduit. STI-1221D FEATURES •UL Listed to U.S. and Canadian safety standards. •MEA Approved. •Helps prevent accidental and intentional damage or vandalism. •Easy access for service. •UV-stabilized. •Spacer easily mounts over exposed conduit. •Polycarbonate rated -40ºF to 120ºF (-40ºC to 49ºC). •Lifetime guarantee against breakage in normal use. Light Derating Factor •47% - Generic Values •34% - ADT Security - ADTG1-V Series •26% - Amseco - SL24W-153075 •26% - Amseco Colored Lenses - SL24W-153075 - A,B,G, or R •26% - Amseco Colored Lenses - SL24C-3075110 - A,B,G, or R •26% - Amseco Colored Lenses - CSL24W - A,B,G, or R •26% - Amseco Colored Lenses - CSL24C - A,B,G, or R •31% - Detection Systems - GES24 Series •45% - EST / Edwards - 2440S Series •45% - EST / Edwards - 202 Series •34% - EST / Edwards - G1-V Series •34% - EST / Edwards - G1-HV Series •34% - EST / Edwards - G1-HOV Series •34% - EST / Edwards - EG1-V Series •34% - EST / Edwards - EG1-HV Series •34% - EST / Edwards - EG1-HOV Series •57% - Faraday - 2700 Series •31% - Gentex - GES24 Series •31% - Harrington Signal - GES24 Series •45% - Honeywell - XLS202 Series •34% - Honeywell - XLSG1-V Series •34% - Honeywell - XLSG1-HV Series •34% - Honeywell - XLSG1-HOV Series •26% - Mircom - FS-240 •45% - Mircom - MS Series •34% - Mircom - MG1-V Series •34% - Mircom - MG1-HV Series •34% - Mircom - MG1-HOV Series •45% - Mirtone - MG1-V Series •31% - National Time & Signal - GES24 Series •26% - Potter Electric - AS24-153075R •26% - Potter Electric - AS24-153075W •31% - Secutron - GES24 Series •45% - Siemens - 202 Series •34% - Siemens - G1-V Series •37% - System Sensor - SS24110ADA •61% - System Sensor - P2, PC2, P4, PC4, SX, SC •34% - Ziton Pty LTD - ZG1-V Series