ENTORThe 20D681K is a varistor with 560V and 1120V rated voltages, 6.5KA of surge current, and a through hole mounting style. It is manufactured by Coventor and is compliant with RoHS (Reduction of Hazardous Substances) requirements. Varistors are non-linear, voltage-dependent resistors which are commonly used in circuit protection and AC power applications. This particular part can be used to reduce transient overvoltage to acceptable levels, limiting voltage transients that could lead to equipment failure or other electrical problems.