Copper Compression Lug, 1 Hole, No. 4 American Wire Gauge (AWG) Flex, Flared Barrel, 3/8 Inch (9.5 mm) Stud, Can be used with flex conductor class: K, M, and Diesel Locomotive, Flared entry prevents bent back strands when inserting fine strand conductor into barrel, Color-coded barrels marked with Panduit die index numbers for proper crimp die selection, Inspection window to visually assure full conductor insertion, Tin-plated to inhibit corrosion, UL Listed and CSA Certified to 35 KV and temperature rated to 90 Degrees Celsius when crimped with Panduit crimping tools and dies, Tested by Telcordia - meets NEBS Level 3, American Bureau of Shipping Approved.