Our horns are dependable and offer totally reliable operation. The metallic sound of a normal-tone horn is clearly audible whatever the environmental and weather conditions. Features Harsh, penetrating sound for long distances Unrestricted sound propagation to the front Solid mechanical design Microporous Teflon filter for pressure equalization Weather-proof Not affected by rust and flying stones With EC and ECE approval Following is the raw material used - Outer Body - CRC Sheet Clamps - Spring Steel Amature Pin - Mild Steel Diaphram - Spring Steel Screw Ring - CRD Sheet. Point for Current - 4 mm thickness Dishtone - CRC Sheet.