The RN55D5621F is a surface-mount low profile, industrial-grade, precision, high-power thickness-film resistor manufactured by TRW. It is a 1/6w resistor and has a maximum working voltage of 250v. It has a tolerance of ±0.1%, a TCR of ±100ppm/°C, and a power rating of 125mW. This resistor also has a wide temperature range of -55°C to +250°C, making it suitable for a variety of applications in industrial, military, aerospace, and other extreme temperature environments. The RN55D5621F is commonly used in precision current and voltage measurements and is a reliable solution for a variety of high-power and high-temperature applications.