Abstract: An accessory to a bed knife gage and bar that holds the bar in place against the rollers on a lawn mower cutter. The accessory comprises a movable permanent magnet attached to a rod and handle, the rod, in turn, attached to the bar. Engagement of the permanent magnet with the mower cutter bed knife holds the bar and gage in place obviating the need for the user to hold the bar in place while using the gage.