K2 Engineers Offers Wire Wound Resistors with specially designed IP 20 rated enclosures. Multiple Resistors are series - parallel connected to realize the ohmic value and power rating. The Resistor Construction is fully welded and are coated for maximum environmental protection. As the resistive elements are fully supported on ceramic cores, heat dissipation is efficient as compared to the open coiled ones. The SR (E20) Series resistors are widely used in the elevator & material handling industries.