STI 1221D Stopper Dome and Strobe Damage Stopper and Open Back Box with Conduit Knockout

Protect critical notification devices and maintain reliable alarm performance with the Safety Technology International STI 1221D protective cover. Designed for commercial and institutional security, fire alarm and monitoring installations, this damage stopper provides tough, transparent protection that preserves strobe visibility while preventing vandalism, weather and UV damage. Constructed from thick polycarbonate (PC) with an enclosed back box and conduit knockout, the STI-1221D streamlines surface-mount wiring and keeps low-voltage connections secure. At 8.5" H x 6.5" W x 5.75" D the cover fits common horn/strobe units without compromising light output; it is UL/cUL Listed, ADA compliant and MEA 49-00-E approved for code-conscious projects. The clear dome allows visual monitoring of device status and offers easy access for service to reduce maintenance time. Ideal for schools, healthcare facilities, transit hubs and retail environments where surveillance, security and uninterrupted signaling are essential. Specify the STI 1221D for dependable protection of strobes and horns—contact your distributor to order or discuss installation details.

• Heavy-duty clear polycarbonate shields strobes and horns from vandalism, weather and UV — preserving signal visibility and reducing downtime
• Enclosed back box with conduit knockout speeds surface-mount installation and simplifies low-voltage wiring for fire and security systems
• Transparent design maintains effective light output and ADA compliance while protecting devices in high-traffic areas
• UL/cUL Listed and MEA-approved for easier code compliance and faster inspections on commercial projects
• Easy service access and a 3-year limited warranty minimize maintenance time and provide long-term reliability