Semiconductor The MCR03ERTJ122 is a chip resistor manufactured by ROHM Semiconductor and is a surface mount part. The resistor is 1.2 KOhms, has a tolerance of ±5%, has a power rating of 1/10 W, and is an 0603 size with RoHS compliance. The resistor must be handled with care due to its small size and delicate connections. It is primarily used in industrial and automotive applications. This chip resistor is incredibly small, acting as a fast, reliable and efficient way of forming accurate resistors in a small space.