After a year of fighting the Arca Clamp which was factory mounted on top of my Arca-Swiss Monoball p0 Hybrid Ball Head, I have discovered a simple means of replacing it with a Really Right Stuff Lever Clamp. I was unaware of the RRS miniature version (Model B2-40-LR - $105) of their classic lever clamp. To my great surprise, the bolt holding the old Arca clamp on to the p0 body was NOT held in place with thread sealant and the old bolt worked fine for mounting the new RRS Lever Clamp. The new clamp is designed to work with a wider range of mounting plates according to RRS. The only trick to the installation was stacking two fender washers under the clamp to allow free rotation of the clamp. I did use Blue Locktite thread sealant during assembly. The new lever clamp works fine and I received extra satisfaction in throwing the useless Arca Clamp in the trash can!!! I have never understood why Arca would supply their wonderful ballheads with such junky clamps!