BLM21PG221SN is a ferrite bead designed to filter high-frequency noise in electronic circuits. It is typically used in signal lines to suppress electromagnetic interference (EMI) and radio frequency interference (RFI). The component is known for its high impedance at high frequencies, helping to ensure clean and stable signal transmission. The BLM21PG221SN is housed in a compact 0805 (2012 metric) surface-mount package, making it suitable for space-constrained applications. It features a low DC resistance and high attenuation, which contribute to its effective noise suppression capabilities.