The AC0402FR-07121KL is a thick film resistor manufactured by Yageo. It is a surface-mount device (SMD) with a resistance of 121K ohms and tolerance of 1%. The package is 0402 inches, which is a 4-pin, surface-mount chip package measuring 0.040" x 0.020" x 0.010". The device has an AEC-Q200 certification, which indicates the product meets the requirements for automotive reliability and durability. It is used in a variety of automotive, military, and consumer applications.