14 gauge passivated Stainless Steel Flush-Mount, Aluminum Housing. Large Palm Activation Button for Help. Tamperproof Hardware. Conformal Coated Electronics. ADA Compliant. NEMA 3R Weatherproof Rating. Telephone Line Powered. No External Power or No Battery Back-up Required. Remote Programming. Extreme Operating Temperature Range 40°C (-40°F) to +60°C(+140°F). FCC & IC Certified, UL 60950 Listed.