A stand apparatus, which can be built and assembled/disassembled in a modular manner, is shown and described. In particular embodiments, a bushing for a stand apparatus for arrangement in an operation theater, comprising a coupling part, by means of which the bushing can be mounted on a connecting component of the stand apparatus about a rotational axis and/or along the rotational axis in a height-adjustable manner—in particular, on a spindle—and a section on which the bushing can be connected to a support arm of the stand apparatus, wherein the section is a mounting section, by means of which the bushing can be mounted on the support arm in a reversible manner—in particular, by means of one or more fastening means. Further embodiments comprise a support arm for fastening to a bushing, as well as a support system, consisting of at least one such bushing and one such support arm.