 This type of cable is very hard-wearing, resistant to oil and moisture, and resists the kinking that can result in internal conductors unlaying and twisting, which is a common problem with the SJTW cable often used in household-grade extension cords.However, older cable made using natural rubber is susceptible to dry-rotting, particularly with the heat generated by lighting equipment.This can cause the insulation to fail and expose or short circuit the conductors leading to shock or fire hazard if old cable is not inspected regularly and replaced as needed.