Piers for astronomical telescopes ensure a very stable base. They are suitable for mounts that are permanently fixed in a garden, on a balcony or in your own observatory. They allow the telescope to remain permanently installed and the polar alignment to be carried out very accurately.
Piers are either designed to be bolted permanently to the floor or have their own feet. The transition to the classic tripod is rather fluid.
Pier extensions are not complete stands. They serve only to set the mount higher. This may be necessary in order to prevent the telescope from fouling the tripod legs or to provide a more comfortable height for looking through the telescope.