Retort stand

Retort stand bosshead and clamp
In chemistry laboratories, a retort stand, also called a clamp stand, a science retort stand, a ring stand, or a support stand, is a piece of scientific equipment intended to support other pieces of equipment or glassware, for example, for instance, burettes, test tubes, and flasks.

A typical ring stand consists of a heavy base and a vertical rod, both of which are usually made of metal. A number of accessories, such as various types of clamps and rings, can be attached to the rod by thumbscrews, at whatever both height and direction are necessary to support the target device.