THIS BALL IS HELD IN PLACE BY A THREADED FASTENER. BECAUSE THE BALL IS HELD FROM BEHIND WITH A MACHINE SCREW, THERE IS NO INTERRUPTION OF THE SPHERICAL SURFACE. THIS PROVIDES A SMOOTH, CLEAN WORKING SURFACE. THE LOTUS WRENCH SHOWN ON PAGE 5A OF THE KINEMATIC COMPONENTS CATALOG #105 IS AN EXCELLENT TOOL FOR INSTALLING THESE BALLS FROM THE FRONT. THREE OF THESE BALLS PROVIDE A VERY HIGH QUALITY SUBSTITUTE FOR A CONICAL CUP OR TRIHEDRAL CLAMP. THESE BALLS ARE AN EXCELLENT CHOICE FOR THE THREE SPHERICAL CONTACT POINTS IN THE KINEMATIC SYSTEM.