A TAKE OFF ON THE SINGLE BALL BAR FOR INTERIM EVALUATION IS THE BALL BAR KIT WHERE A SPECIAL DOUBLE BALL BAR CLAMPING DEVICE (PART # FS-2BB) IS SUBSTITUTED FOR THE STANDARD SINGLE BAR CLAMP. THE TWO BALL BARS ARE USUALLY ONE SHORT 300 MM (11.8 INCHES) AND ONE LONG 600 MM (23.6 INCHES) OR 600 MM AND 900 MM (35.4 INCHES), SPHERE CENTER TO CENTER LENGTH.
