Nikko Stirling Mountmaster 3-9x40 4 Plex with Weaver Rings Scope, Black SHOCK TESTED. The Nikko Stirling MountMaster 3-9X40 4PLEX will stand up to real use. FULL METAL ALLOY adjustment houses for greater reliability.Scopes are nitrogen filled at the factory NITROGEN FILLED scopes are filled at the factory for fog and waterproofing Scopes come supplied with 3/8 Inches or Weaver quick detachable mounts Objective focus, Parallax adjustment, Fast focus ocular lens Fast focus ocular lens Objective focus Parallax adjustment