ROAD POWER extra heavy-duty booster cables feature Polar-Glo clamps and T-Prene jacket insulation. This enhanced line of booster cables ensures the highest levels of user-safety and assures dependability in the most extreme climate conditions. The Polar-Glo clamp is ergonomically designed so that it can be easily handled by everyone and it attaches itself firmly to both top and side post batteries. The clamps triple-polarity identification includes color coding, intent stamping, and glow-in-the-dark labels. In addition, all energized clamp surfaces are shielded to avoid short circuits and all conductive clamp surfaces are recessed to prevent accidental contact. T-Prene insulation was chosen for the wire jacketing material because it remains flexible even under the severest temperatures and is oil, chemical, and water-resistant. Heavy-duty booster cables are made using a 4-gauge wire and performs best with any vehicle including cars, trucks, or SUVs. This booster cable is UL listed in 16' lengths and packaged in a retail-style box designed for easy display.