Aluminum: .040 Rust resistant aluminum. Painted with baked on enamel finish, Resists marring, corrosion and humidity. Furnished with rounded corners and 4 mounting holes. Best choice for indoor and outdoor applications. Lightweight and easy to install.
OSHA STANDARD 1910.97 NONIODIZING RADIATION
(a) (3) Warning symbol. (i)
The warning symbol for radio frequency radiation hazards shall consist of a red isosceles triangle above an inverted black isosceles triangle, separated and outlined by an aluminum color border. the words "Warning-Radio-Frequency Radiation Hazard" Shall appear in the upper triangle