The optional 12-24 Tripod Screw Set for Grip Base M1 for an existing Grip Base M1, consists of two sets of 12-24 Tripod Screws and 12-24 Tripod Screw Spacers.
*For an Ikelite housing which has 12-24 UNC size screw holes of 76mm/3in center-to-center distance on its base, the modified Grip Base M1 shipped after March 2012 is necessary. The Grip Base M1 shipped before March 2012 is not compatible.