The HolRS3921-5W-4mR-1% with 5W 4mO 3921 Current Sense Resistors/Shunt Resistors ROHS manufactured by Milliohm is a resistor that is designed to sense small currents in an electrical circuit. It can be used to measure current flow, monitor device performance, or detect overloads in the system. The resistor features a 5 Watt rating, 4 milliohm resistance value, a 3921 case size, and a tolerance of 1%. It is manufactured in accordance with RoHS standards for environmental sustainability. The resistor can be used in a variety of applications, such as motor control, LED lighting, battery management, and robotics.