Battery lugs are the eylet ends as used on the end of a battery cable. These lugs are designed for use in combination with 4-gauge universal bulk battery cable to create a perfect fitting battery cable for most stock or custom applications. - With 3/8" (9.5mm) diameter eyelet - Solder-on type lug - For 4-gauge (5.19mm diameter / 19mm²) battery cable Note: Solder slugs (available as 951765) are convenient pre-measured amounts of solder. They are inserted into the battery lug; and placed in a vice. Then the battery lug is heated and battery cable gently pushed downwards for the perfect connection. Do not forget to slide a piece of heat shrink tubing around the battery cable first to make a weatherproof seal afterwards.