This thing has some known problems but if you're like me throwing around a big scope on your EQ6R with a long image train, you need the clearance from your tripod legs so you really have no choice but dealing with this. What i found worked to keep it from rotating on me was to use a silicon pad between the pier extension and the tripod. This pad acts as a friction layer and compression layer between the botton puck and the tripod - where it would normally rotate because there was no friction. Problem solved. It should include a silicon pad in the kit. if you don't have a silicon pad thin enough, cut open a bicycle tube and lay it across (wash off the talc powder if your tube has it) and use that as a friction layer. To make the silicon pad work, leave the hand screw slightly lose and insert the extension and put the side screws in and tighten them up and then tighten the hand bolt as much as possible.
I purchased this in anticipation of wanting some additional clearance between my camera/focus tube on my SW Esprit 100ED and the tripod legs of the SW EQ6-R Pro mount. Construction is suitably heavy, but not of outstanding quality. Noticeable lack of concentric fit between the internal mount plate adapter and the outer support tube. Enough so that the threads of the attaching cap screw on that side are visible between the adapter plate and the tube even after everything is tightened down. The tube design is simple, but forces a 'permanent' attachment of the pier to the mount, making it impossible to store/stack the mount sitting on its base. Not a show stopper, but not well thought out in my opinion. A better design would have had 'ports' to access the top attachment fitting to remove the mount from the extension, rather than the mount+extension having to be placed/removed on the mount as a single assembly as is required by the current design. The show stopper is the lack of any means to lock or other wise prevent the pier extension from rotation on the tripod. This a particularly egregious oversight since it takes almost no effort to move the entire assembled mount/OTA about the azimuth with just pressure from one finger (and not hard pressure). This is with the central mount bolt tightened as tight as it can be gotten. It is pointless to spend 30 minutes getting a perfect polar alignment to have a slight tug on the cable, a filter slide, or just touching the OTA and ruining the PA. Some have tried to add washers/material between the pier to at least make it harder to rotate with limited success. It shouldn't be necessary, period. The only option that could work with the current design would be to modify it to utilze an additional polar alignment stud in the tripod to lock the pier against. If it had side ports, cap screws could be used to lock it in place against the top of the tripod plate. There are a multitude of design modifications that could have/should have been implemented before this was marketed. None were.
Sturdy but not at all rotationally stable down at the tripod end. Tighten the tripod center nut all you want. You can still rotate the pier by hand, easily! Problem is poor design. Need another dowel/keyhole connecting the pier at the tripod. It's not there. Now I must create a DIY project to stabilize it in the azimuth direction. I like the pier but NOT stable in the azimuth direction. Fast slews will de-polarize your scope. I hate when that happens!