This dialog allows you to quickly set a different interval size for the snap grid. The snap grid pulls the cursor to the nearest point on its defined grid.
From the schematic editor:
Use the View » Grids » Set Snap Grid command from the main menus.
Choose the Set Snap Grid entry on the Grids drop-down () of the Utilities toolbar (View » Toolbars » Utilities).
Use the field in this dialog to enter the grid interval as required.
The entered grid size is reflected at the left-hand side of the status bar and also in the General region of the Document Options view of the Properties panel.
In the workspace, cycle forward (G) or back (Shift+G) through predefined grid settings. The settings available are determined by the chosen presets as defined on the Schematic - Grids page of the Preferences dialog and the current measurement system in force (Imperial or Metric). If you change the grid size in this manner, your entered setting will be lost since cycling only involves the currently chosen preset interval settings.