VFM DC Power Line Filters CUI Inc VFM DC Power Line Filters range from 30W to 75W and are available in board-mount, chassis-mount, and DIN-rail configurations. These filters provide 98% efficiency and meet the IEC/EN 61000-4 standard, and the VFM-30-UW and VFM-50-UW series both comply with the EN 50155 railway standard. CUI Inc VFM DC Power Line Filters operate over a -40°C to +100°C temperature range and are ideal for reducing EMI noise upon the DC power line.