Wire resistor in an aluminum housing an additional heat sink with high thermal conductivity is recommended. Surface: anodized Connections: Copper, tin-plated Potting: Silicone with high thermal conductivity Winding with uniform pitch Limit voltage: 265 V R-tolerance: ± 5 % WIAL 50 Rated power for resistor as shown without heat sink: 20 W with additional heat sink: 50 W Cooling surface: 930 cm2 2 x 1.5 mm WIAL 10 Rated power for resistor without heat sink as shown: 6 W with additional heat sink:12 W Cooling surface: 415 cm2 2 x 1.0 mm