These vertical featherboards are an excellent accessory for safer routing and can be used on their own or with horizontal featherboards that are also available separately. They simply attach to your router table fence with the supplied T-bolts and provide extra support for the workpiece as it is being passed across the cutter. The amount of applied pressure is sustained over a wide area so you are less likely to experience breakout or chatter on the workpiece. The UJK vertical featherboards should be positioned at each side of the cutter offering downward pressure on both the infeed and outfeed sides of the table.