The FTR20D471K is a Varistor with a Through Hole, P=10mm RoHS manufactured by FTR. It has a voltage range of 385V to 775V, and a rated surge current of 6.5KA. This device is used to protect circuits from transients and other electrical disturbances by serving as a voltage-dependent resistor. It can help provide surge protection for components, or as part of a transient suppression network. The FTR20D471K is RoHS compliant and lead free, making it ideal for use in applications where environmental regulations need to be adhered to.