Hey Andy,
If you have Herbie's Way Excellent mat, try out the matching clamp made for it....herbie's Sonic Stabilizer puck. Its a combo that should not be dismissed, and you may find much more satisfaction. Its $30 but comes with a trial offer like all of Herbie's products.
KAB's clamp operates by attaching to the spindle, right? herbie's stabilizer does not.
matt