VTK-6222-PK is an external attachable power isolation kit for nROK 6222 to protect against sudden power surges. Rated power is 150W, constituting two types of models with 2:1 wide but different input ranges 16.8 ~ 31.2VDC and 67.2 ~ 143VDC, suitable for railway systems used standard input voltages such as 24VDC and 110VDC.