While sealed switches are designed to seal out harsh invasive contaminates, they DO NOT seal the panel-hole cutout. Hence these very same contaminants may "leak passed" the bushing, endangering internal circuit components. The APM Hexseal stainless steel bushing seal, with its bonded silicone exterior was designed to control potential leakage. Sizes are available to fit most switches and circuit breakers. It is a UL-recognized component, IP66/68 rated, and RoHS-compliant. HEXSEAL panel bushing switch seals operate in a temperature range of -94°F to +400°F (-70°C to +204°C). These seals can be mounted from either side of the panel and are resistant to salt spray, sunlight, ozone, weather, fungus, and most acids and lubricants.