The Bosch Horn Loudspeakers are specifically designed and approved for installations where explosive gas-air mixtures are likely to be present. They are suitable for use in all gas groups including hydrogen. · ATEX approved · BASEEFA-certified · CENELEC-approved · Glass reinforced polyester with strong, fire retardant properties · Reduced maintenance costs · Corrosion and chemical resistance · Water- and dust protected to class IP 66 and IP 67 · Complies with international installation and safety regulations