Controls the size of the object snap target box.
Object snap applies only to objects inside or crossing the object snap target box. The APBOX system variable controls whether the object snap target box is displayed. The number of pixels you enter using APERTURE controls the size of the object snap box. The higher the number, the larger the target box.
You can also change this setting in the Application Preferences dialog box, Cursor & Selection tab.
APERTURE controls the object snap target box, not the pickbox displayed at the Select Objects prompt. The object selection pickbox is controlled by the PICKBOX system variable.