What are flatpack resistors in metallic case?

Metal housed resistors are a good solution for braking resistor, precharge resistors and discharge resistors. The number of the families and the models permits to find the desired component for sure. There are several options regarding: degree of protection, thermal switch included, wires length. In total we have 9 families: RFX, RFK, RFD, RAF, RDF, RFP, RFH, RFZ, RFZ/C.