A plurality of resistors are disclosed herein. The resistor may include one or more resistive elements and a plurality of conductive portions. Openings or slots, which can be configured to adjust temperature coefficient or resistance (TCR) values of the resistor, are formed in the resistive elements. The shape, quantity, and orientation of the openings or slots can vary. In one aspect, header assemblies are provided for securing or holding pins relative to the resistors.