Superstack 

Superstack (currently Superstack II and Superstack 3 devices are available) is a range of stackable mid-range devices from 3Com.  It comprises a set of managed and unmanaged hubs and switches which generally conform to the following specification:

They are rack-sized units, designed to fit into 19" cabinets in wiring closets, communications rooms or computer rooms.  They can also be shelf mounted, and are supplied with rubber feet.  The units can be connected together to cater for larger networks.  

The connection (or stacking) method is not consistent across the range, and can be confusing.   For instance, you cannot stack a Hub 500 with a Switch 3300 - the interfaces are not common.  It is the stacking ability, however, that make the Superstack devices so flexible.  Need to know more?  .

See also: SuperstackII & 3  Matrix Connection