The FBSHS0603-121-301R is a 0603 (6.0mm x 3.2mm) surface-mountable ferrite bead with the RoHS certification, manufactured by Koher. It is made of non-resonating ceramic material, designed to suppress high frequency noise and offer high-frequency electromagnetic interference (EMI) filtering. The device is suitable for high-speed switching power supplies, clock generation, communications, and various digital and analog circuits. It has a low DC resistance, and a high impedance (121 Ohms) and high attenuation (30 dB), which makes it suitable for use in narrow-band applications.