Thomas and Betts Lugs are part of the Color-Keyed System providing consistent and reliable connections. Compression Lugs are manufactured of wrought copper that is electro-tin plated to prevent oxidation and corrosion. They are Color-Keyed to match colored bands on the installation dies to provide technicians with the assurance that they are crimping the T and B lug with the appropriate compression die. A die index number is noted on each lug for additional verification and to simplify inspection.