B72210S271K551 is TDK's part number for a EPCOS Filtering Choke. This part is a single-phase common mode choke, which is designed to reduce electrical noise and high frequency signals in device power supplies and low-voltage DC supply lines. It has a rated inductance of 270mH and is rated for a continuous operating temperature between -40°C and +125°C. The product is also RoHS compliant and is rated to work at a maximum operating voltage of 250 VAC.